THE BULLETIN

of the

UNITED STATES GOLF ASSOCIATION GREEN SECTION

Vol. 7 

Washington, D. C., April, 1927 

No. 4

Contents

Page

Winter Injury of Turf. By John Monteith, Jr.....................................................  62

Care of Bermuda Putting Greens. By Dr. Thomas P. Hinman, Atlanta, Ga.. 77

Poa Bulbosa. By H. L. Westover and O. B. Fitts................................................ 78

Questions and Answers.............................;...................... ................................. ,... 82

EXECUTIVE

COMMITTEE

Wynant D. Vanderpool, Chairman, 766 Broad 

Street, Newark, N. J.

Russell A. Oakley, Washington, D. C.
Harvey L. Westovh?, Washington, D. C.

H. Kendall Read, Philadelphia, Pa. 
Walter S. Harban, Washington, D. C.
H. Y. Barrow, New York, N. Y.

RESEARCH

COMMITTEE

Russell A. Oakley, Chairman, Washington, 

Harvey L. Westover, Acting Chairman, Wash­

D. C.

ington, D. C.

O. B. Fitts, Associate, Washington, D. C.
G. T. Cunningham, Executive Secretary, Wash­

ington, D. C.

ADVISORY COMMITTEE

W. A. Alexander, Chicago, Hl. 
Eberhard Anheuser, St. Louis, Mo. 
A. C. U. Berry, Portland, Oreg. 
William F. Brooks, Minneapolis, Minn. 
N. S. Campbell, Providence, R. I. 
Wm. C. Fownbs, Jr., Pittsburgh, Pa. 
F. H. Hillman, Washington, D. C. 
Thos. P. Hinman, Atlanta, Ga. 
Frederic C. Hood, Watertown, Mass. 
K. F. Kellerman, Washington, D. C. 
Norman Macbeth, Los Angeles, Calif.

E. J. Marshall, Toledo, Ohio. 
W. L. Pfeffer, St. Louis, Mo. 
George V. Rotan, Houston, Tex. 
Sherrill Sherman, Utica, N. Y. 
Frederick Snare, Havana, Cuba. 
James D. Standish, Jr., Detroit, Mich. 
W. R. Walton, Washington, D. C. 
Alan D. Wilson, Philadelphia, Pa. 
M. H. Wilson, Jr., Cleveland, Ohio. 
Frank L. Woodward, Denver, Colo.

The Bulletin is published monthly by the United States Golf Association Green Section, P. O. 

Box 313, Washington, D. C., at Room 7207, Building F, 7th and B Streets N. W.

Address all MAIL to P. O. Box 313, Pennsylvania Avenue Station, Washington, D. C.
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Entered as second-class matter. April 21, 1926, at the postoffice at Washington, D. C.. under 
the Act of March 3, 1379. Copyrighted, 1927, by the United States Golf Association Green Section.

62

April, 1927

Winter Injury of Turf

By John Monteith, Jr.

Winter injury of turf has for several years been the subject of 
much debate among greenkeepers and others interested in turf main­
tenance. As is customary in such general discussions there has been 
evident an attitude of insistence that all such damage is due to a 
single cause. One group maintains that winter injury of northern 
grasses is nothing more than poor drainage and so sure has it been 
of this conclusion that all other theories or observations have been 
discredited and classed as nonsense. Another group maintains that 
there is a fungus or mold which kills the grass as the snow melts and 
that poor drainage has nothing whatever to do with winter injury. 
There have been other explanations presented and as dogmatically 
supported. In reality the opposing factions may all be right in their 
conclusions, for their own local conditions, but each has been equally 
wrong in insisting that his pet “cause” was the only one which should 
be considered. This article is an attempt, not to explain all cases of 
winter injury, but to summarize the present information available 
on the principal types of these important golf course problems. 
Those who choose to think of winter injury as due to one cause, no 
doubt will regard this discussion as an attempt to complicate matters 
by subst-tutmg separate explanations for our hitherto single “winter- 
killing.” The fact remains that Nature has not so simplified matters 
for the convenience of the greenkeeper and that unless we distinguish 
between them we are unable to intelligently guard against the dam­
age, for it is obvious that control measures must vary according to 
the cause of the injury.

It frequently happens that more than one type of winter killing 
is found on the same green and there may be an overlapping which 
renders a positive diagnosis extremely difficult or impossible. On 
the other hand, a consideration of causes and symptoms, as will be 
pointed out later, should make it possible for even the most casual 
observer to distinguish between them. No attempt will be made at 
any general evaluation for, although one type may be more widely 
distributed than another, the relative importance will vary with the 
locality; as an example, the “most important” type of injury in New 
England, Minnesota and Canada may never occur in Virginia or 
other southern districts.

In looking over the published references of winter injury to turf, 
one is frequently unable to determine to what the writer had refer­
ence, but in many cases the type of damage is quite apparent from 
its description. We have reports from Cahada, New England and 
many of our northern states of a spotted condition which in some 
respects resembles large brown-patch. Somewhat farther south 
there is a belt where the injury reported is almost invariably asso­
ciated with depressions in which water collects and freezes. Still 
farther south neither of these types appears to be troublesome but in 
that section the problem is largely one connected with the freezing 
of Bermuda or other southern grasses. In the Gulf States and Cali­
fornia there is a spotting which is described as practically identical 
with brown-patch. There are occasionally complaints of other dam­
age occurring on turf during the winter months but usually the 

April, 1927

63

descriptions of these have been vague or apparently confused with 
one or more of the above.

The well recognized types of winter injury which will be dis­
cussed here are for convenience grouped according to their causes; 
namely, those due to freezing, both on new seedings and on estab­
lished turf; those due to poor drainage or ice sheets; and those on 
northern courses due to fungi. The “brown-patch” of the southern 
states and California, damage due to tramping on grass when it is 
first frozen or during a period of alternate freezing and thawing, and 
various others that have been reported should also be considered. 
They will be omitted, however, chiefly because of our present limited 
information, or because of the restricted or sporadic occurrence of 
those of minor importance.

Freezing Injuries to Southern Grasses

In considering any winter injury one naturally first questions 
what portions of the loss may be attributed solely to freezing. Para­
doxical though it may sound, the most serious injuries to golf course 
grasses due to freezing occur in the south.

Most of the native southern plants are extremely sensitive to low 
temperatures. This applies also to the grasses and many, such as 
Bermuda grass, are killed to the ground by the first heavy frost. 
As a rule this injury is only seasonal, for the roots are not killed and 
there is complete recovery with the return of warm weather. In 
their northern range, however, freezing may entirely destroy large 
areas of such grasses, in either new plantings or old, established turf.
On courses where it is desirable to keep the greens in play 
throughout the winter, the problem is one of providing a succession 
of grasses for the different seasons; Bermuda grass for summer and 
a cold-resistant grass for winter, one replacing the other with the 
least possible interruption of play. It is customary to seed rye grass, 
redtop or other northern species directly on the Bermuda grass in 
early fall. When the summer turf is checked by the cold the new 
seedlings are ready to take its place and provide a good playing sod 
for the winter months. Again in spring when it becomes too warm 
for these northern grasses, the Bermuda will appear and replace 
them. This method is so well established as to hardly call for dis­
cussion here. However, it necessitates an annual seeding of the 
greens and has other undesirable features. It appears probable that 
in the not distant future this method will be replaced by that of using 
perennial grasses for both the summer and winter turf. Poa bulbosa 
has shown much promise in combination with Bermuda grass par­
ticularly for fairways. Each of these grasses is perennial but with 
entirely different temperature requirements for growth. As one de­
velops the other becomes dormant, but is not killed; each being ready 
to reappear and replace the other grass as the seasons change.

The problem of maintaining Bermuda grass on greens in the lati­
tude approaching its northern limits is a somewhat more difficult 
problem. In this section, where fall seeding for winter turf is not 
practiced and where no attempt is made to have the greens in condi­
tion for winter use, there is the danger that Bermuda and other 
southern grasses will be killed by exposure to low temperatures. 
There have been cases reported where a covering of straw has proved 
effective in protecting such grass during the months when it is dor­

64

April, 1927

mant. This practice has been condemned because of the apparently 
harmful results obtained in covering greens with straw in the 
northern states, especially in the vicinity of Minneapolis. However, 
since the injury there is chiefly due to an entirely different cause it 
appears unwise to question this practice on the basis of harmful con­
sequences in the north. On the other hand, there is some question as 
to whether the necessity for such a covering does not indicate that 
the wrong grass is being used for greens. Our northern turf grasses, 
particularly bent, are frequently found to flourish much farther 
south than was formerly supposed to be possible. With better 
methods of maintenance during the hot summer months, particularly 
in checking the ravages of brown-patch, it is likely that many clubs 
in such districts could well afford to convert their putting greens to 
bent rather than worry about the loss of Bermuda turf during the 
winter months. Another possible means for avoiding this annual loss 
is by the selection of strains of Bermuda grass more resistant to cold. 
In most of our cultivated crops there are varieties which are much 
more resistant to low temperatures. The same variation is likely to 
occur in any of our turf grasses, although little effort has been de­
voted to such improvements.

Freezing Injuries to Northern Grasses

Most of our best northern turf grasses are extremely resistant to 
cold. Some of those used in golf course mixtures disappear during 
the winter but their loss is usually of little importance. The cases 
are indeed rare where a well established sod of northern grass is 
killed by simply being exposed to low temperatures.

One frequently finds that new seedings which made a good start 
m the fall are completely destroyed during the winter months, appar­
ently due entirely to freezing. As is the case in many crops, low 
temperatures harmless to older plants are disastrous to seedlings 
which have not become sufficiently well established. This loss can 
usually be avoided by earlier planting, but where this is impractical 
the customary procedure is to take a chance on late planting and to 
rely on reseeding early next spring wherever the stand has been 
destroyed or thinned by winter exposure.

<® fescue turf. Nakoma Golf Course. Madison, Wis. On this ereen »

F,«- 2’ .,F?**‘nF 
was built m imitation of one of the Indian mounds commonly found throughout this^section of the 
country. Wind keeps the snow swept from this mound so that throughout the winter the grass is 
exposed to low temperatures and the drying effect of the wind, resulting in the light brown color 
-Kt t I
of the turf in the bare areas as contrasted with the dark green where it was 
of snow. The photograph shows the lighter appearance of the £rass along the crest

njtnry a*no«"t8 more tha" * sbKht «**'-ySpring gXth.'Th^whiJi 
areas at the left are of the much more serious winter-killing due to inadequate provision for sur­
pro¥,s,on Ior sur
face drainage so that water collects during the winter 

April, 1927

65

Although well established northern turf is seldom killed by low 
temperatures, it nevertheless is sometimes noticeably damaged. 
There is frequently a lifting or “heaving” of the plants well up from 
the soil level; a condition more likely to occur on one type of soil 
than another, especially where turf is thin, consequently it may be 
much worse on one part of the course than on the rest. This lifting 
of the plants and the resulting breaking of roots may kill some of 
the grass, and probably checks all of it to some extent. After such 
turf is rolled there is usually practically complete recovery, so this 
disturbance is by no means as serious as it may at times appear.

Another type of injury which is associated chiefly with low tem- 
peratures is that where turf is swept free of the normal covering of 
snow and appears bleached and lifeless when the rest begins to show 
green in the spring. Such areas are generally limited to knolls or 
ridges, from which snow is easily blown and which are constantly 
exposed to extremely low temperatures, combined with the drying 
influence of wind. This type of cold injury occurs chiefly on thp 
more northern courses but even there the damage, seldom sufficient 
to actually kill the grass, simply results in a loss of the leaves and a 
slight delay in early spring growth. As a rule no preventive meas­
ures are resorted to but some greenkeepers feel that a covering of 
branches or some material to catch and hold the snow on a few most 
exposed areas will more than repay them for the extra labor involved.
Water and Ice Injuries

Throughout a large part of the country the most important turf 
problem during the winter months is that known generally as “wintei* 
kill” or “ice injury.” This damage appears as large, irregularly 
shaped, discolored areas which become evident as soon as the ice and 
snow have gone. When the color is yellow or light brown the dam­
age is usually of minor importance for the grass is only temporarily 
checked; but where it is a dull brown or gray the chances are that 
most of the grass is dead so recovery of the turf will be very gradual 
at best and such areas will ordinarily require replanting. In any 
case these unsightly patches remain long after the green should be 
in good condition and it is not. infrequently found that their effect 
is noticeable throughout the season.

The real cause of this type of injury has not been definitely de­
termined. The location of the dead areas indicates that it is due 
to poor drainage, the formation of pools of water and the alternate 
freezing and thawing of these accumulations. Various explanations 
such as, ice acting as a lens to injure the turf beneath, cutting off 
the plant s supply of air by the ice sheet, “drowning” of the grass 
by the standing water, and many others have been suggested to 
account for this condition. It seems probable that the injury is due 
to a combination rather than to any one factor. Regardless of the 
actual cause, we do know that it is in some way correlated with water 
standing on turf during the winter months for it invariably occurs 
m depressions where water is likely to collect and remain for long 
periods. Occasionally it is found where there apparently is sufficient 
drainage, but in such cases it can usually be accounted for by a bank 
of snow or some other obstruction preventing the rapid draining off 
of surface water.

66

April, 1927

Although “winter kill” is ordinarily associated with the forma­
tion of ice sheets, it is a well recognized fact that a mere covering 
of ice does not ordinarily injure turf. The so-called “shell” ice, with 
an air cavity beneath, may act as a protection to the grass rather 
than injure it. Skating rinks are often made by spraying water on 
turf until there is a layer of ice several inches thick. The fact that 
these rinks frequently cause little or no damage indicates that such 
a covering in itself is not sufficient to kill grass. “Ice storms” 
occasionally cover entire courses with a sheet of ice which may 
remain in some places for many days or weeks and yet produce little 
or no turf injury.

Fig. 2. Winter-ldll due to water and ice. A ridge across the entire width of this green serves as 
r.rTi ,nt'^ler,nK W,t!’ *urface drainage. A very slight slope tends to drain the water toward the 
n ’“’‘•’Ji * ™?nnd wh,ch effectively prevents its escape in that direction.
The ton 
The top and left side of the ridge (northern exposure), are swept free from snow and the craw has 
been somewhat discolored, although not permanently injured, by exposure to wind and cold This 
same ridge in summer is troublesome due to drying out and “scalping” by the mower. Again the 
question: Why build such abrupt ridges on greens?

The damage ordinarily occurs only where there is no outlet for 
the melted ice, where the water collects and remains for some time 
under the ice or in open pools after this covering has disappeared. 
It must be remembered that when soil is moist with the usual late 
fall oi eai ly w inter precipitation it soon loses its customary porosity 
when the first hard freeze binds the upper layer into a solid sheet. 
Consequently, when rain or melted snow settles in depressions which 
have no surface outlet the water must stay there until removed by 
the gradual process of evaporation or until sufficient openings are 
melted through the frozen layer of soil. In either case these pools 
remain for many days, or even weeks, subjected to the alternate 
fieezing and thawing which appears to be in some way responsible 

April, 1927

67

for the injury to the turf beneath. Since such accumulations of 
water are usually shallow they soon freeze solid and likewise quickly 
thaw during warm periods. Therefore, this sheet is ordinarily trans­
parent, the so-called “black” ice, and serves as a pane of glass through 
which the sunlight readily penetrates to the grass and soil beneath 
where the heat is absorbed. Contrary to the usual order of thawing 
ice and snow, these thin layers of clear ice first melt at the bottom 
and thaw upward. There may be sufficient heat absorbed by the 
plants under such a covering to actually stimulate a slight growth 
which is checked again by the next freeze. The effect of this pro­
longed submersion, even though growth is almost negligible, probably 
has somewhat the same harmful influence on plants as does the 
“drowning” of grass during the growing season. For practical pur­
poses it is perhaps sufficient to recognize that the damage occurs 
where water is held on the turf too long during a time of intermittent 
freezing and thawing.

Control of Ice-Sheet Injury

For this type of injury there is but one permanent solution; that 
is, removal of its cause by providing for proper drainage. This 
does not mean simply the subterranean kind, for many a green which 
is provided with all the most approved systems of tiling and other 
underground drainage is woefully defective in the simple provision 
for adequate surface elimination of excess water. When moist soil 
is frozen it becomes practically impervious to water so that all sys­
tems of subsurface drainage then fail to function.

Fig. 3. Typical winter-kill on a green where surface drainage has been completely ignored. “A 
word to the wise is sufficient”

Frequently the injury is nothing more serious than a temporary 
discoloration. This should be taken as a warning, for although the 
damage may be slight one year, during the following winter under 
somewhat different weather conditions there may be extensive kill­
ing. In a great many cases these depressions are slight and may be 

68

April, 1927

gradually raised by repeated heavy applications of compost during 
the growing season, at such a rate that the process will not interfere 
with play. A small expenditure of money and labor applied in this 
manner will often save far greater expense and inconvenience in 
later years. In addition to insuring against future winter killing, 
this attention to low areas will serve to guard against summer diffi­
culties, for large browri-patch and many other summer disturbances 
are likewise encouraged by defective surface drainage.

When turf has been killed by these ice-sheets, the treatment in­
volves greater expense and greater interruption of play for it will 
be necessary to resod or reseed. In order, to prevent a recurrence 
of the same injury in the future, before replanting, the low area 
should be raised with soil or a suitable “run-off” should be cut. A 
line of tile will not suffice, for surface drainage must be relied upon 
when the ground is frozen.

Some greenkeepers have reported success in preventing injury 
by breaking off the ice-sheets whenever they form. Such a pro­
cedure is apt to do more harm than good for if it is frozen hard to 
the turf there is certain to be some injury to the grass if the ice is 
chopped off. If this sheet is not frozen fast to the-grass, due to an 
air space below, it may be readily removed without injuring the 
plants. In such cases, however, there is nothing to be gained for 
a loose covering of this kind does not injure turf. On the other 
hand, there are conditions where removal of ice no doubt is bene­
ficial. When water settles and freezes in a pocket on a green, if 
done at the right time, most of it can be readily removed without 
injury to the turf. When the sun shines on such ice it will usually 
first melt at the bottom. As soon as there is a film of water beneath. 
it, this sheet can usually be lifted with very little injury to the 
grass. If repeated whenever ice collects in pockets, this process will 
greatly reduce the amount of damage. This should not be interpreted i 
as a recommendation for control of the injury, but merelv as an 
emergency procedure. If the labor involved in such a method were 
applied during the growing season to making adequate drainage for. 
those areas, there would be no necessity for these precautions in 
future winters.

Snow-Mold Injury to Turf

On courses in our northern states and in Canada there is found, 
an entirely different winter injury which is commonly referred to 
as ^nt?r brown-patch ’or “snow-mold.” This type is often serious 5 
m Cleveland, Detroit and ■'•Chicago^'but how much farther south it
determined. It may occur in combination with
the winter kill due .to, poor drainage but more often it is found 
alone and on some courses may be far more destructive than all other- 
forms of winter damage combined.

e« • x S 

Snow-mold injury occurs in patches which are usually roughlv cir- 
to* m outline but may be very irregular in shape. The majority 
of the affected areas are only a few inches across but they vary anv- 
where up to three feet or more in diameter. They are first noticed 
as the snow melts away; at which time there is clearly evident a grav 
moldy growth covering the grass and causing it to decay and 
collapse in a slimy mat, see figure 4. When these patches dry they 
become brown or bleached and, as the healthy grass develops its

April, 1927

69

Fig. 4. Snow-mold developing on turf as the snow melts away. At the lower left is shown the 
melting snow and through the center of the photograph can be seen the gray slimy mats of fungus 
and decaying grass. Later when the turf is dry these affected areas give the spotted appearance 
shown in the following figures

green color, they stand out in sharp contrast (figure 5), giving the 
turf a badly speckled appearance which closely resembles that pro­
duced by large brown-patch. At times this injury amounts to little 
more than a temporary checking of the turf in early spring but fre­
quently the plants are killed and the patches are left bare. In the 
latter case, clover, which apparently is not affected by snow-mold, is 
given a decided advantage for it may develop there with little or no 
competition. Weeds are likewise able to grow unchecked in these 
killed spots and can become well established before the neighboring 
desirable turf grasses are able to offer any competition.

70

April, 1927

Fig. 5. A close-up of snow-mold injury in fescue turf, fairway length. The white portion, measur­
ing 7 inches in diameter, shows where the grass has been killed. A scattering of dark, healthy 
blades can be seen in the bleached mat of dead plants, showing that in this case not all of the 
grass has been killed and that the turf will eventually recover. On close examination one may find 
here several leaves of clover and dandelion. These plants will now be able to develop much more 
rapidly in this injured area than nearby where the healthy grass is better able to compete with 
weeds. Therefore even though these injuries may not be permanent, they certainly serve to encour­
age weeds

These brown or dead areas are caused by a fungus which attacks 
the grass, destroying the leaves and often the entire crown of the 
plant. When the turf is kept wet by melting snow the mycelium 
of this disease-producing fungus is able to grow over it and to attack 
the grass in much the same manner as does the brown-patch organ­
ism during warm periods of summer when there is heavy dew. The 
fungus has been grown by laboratory methods and by' inoculating 
healthy grass in the greenhouse we have been able to artificially 
produce the injury, proving that the fungus found on the diseased 
patches is actually the cause of the damage. “Snow-mold” has been 
lepoited as the cause of serious losses to grain in Europe and in 
this country is frequently a pest in evergreen nurseries Whether 
these are identical with the “snow-mold” of golf courses has not been 
determined, but at any rate the development of the injurv is much 
the same.

Although snow-mold is a fungus, it is by no means the same one 
which causes either the large or small brown-patch. As shown in 
the June, 1926, number of The Bulletin, the fungus causing brown­
patch grows best at a relatively high temperature and is unable to 
develop at the low temperatures in which snow-mold must grow and 
do its damage. A name commonly used to designate this type of 
injury is “winter brown-patch.” The term “brown-patch” is already 

April, 1927

71

so generally misused in applying it to all browned areas in turf, lead­
ing to so much confusion, that it seems best to restrict it to its 
original meaning and to avoid any further general application. The 
name “snow-mold” for this particular fungus is already in common 
usage, is much more descriptive and serves to clearly distinguish it 
from other turf fungi.

Fig. 6. Snow-mold injury. Damage in such locations is hard on the theory that “winter in'ury is 
nothing more than an indication of poor drainage.” The two mounds shown in the upper picture 
are the highest points on this course so they are not troubled with seepage water from anywhere. 
The lower photograph shows the mound at the right in greater detail. In this case the injury has 
developed on one of those useless areas still maintained as a green on which a ball will not remain 
because of the steep slope. Although worthless from the standpoint of play, it has at least served 
nicely to illustrate the point that snow-mold injury is not dependent on poor drainage. The mound 
serves as a trap for snow, as shown in the upper illustration, and as the snow melts the fungus 
attacks the turf

Snow-mold occurs on all the common northern golf turf grasses; 

72

April, 1927

including bents (both seeded and stolon plantings), fescues, blue­
grass, redtop and many of less importance. It is found on greens, 
fairways or rough, but the injury on greens is naturally regarded 
as most important. It is this injury which has made many green­
keepers disgusted with the theory that winter injury is nothing more 
than an indication of defective drainage. Snow-mold very commonly 
occurs on steep slopes, which makes the “defective drainage” ex­
planation appear ridiculous. It is most common where snow accumu­
lates in deep drifts and therefore is frequently found near mounds 
which serve as snow traps. For that reason the injury is even more

Fig. 7. Snow-mold injury below a snow bank where the turf is kept wet by water draining from the 
melting snow above. The mound in the background breaks the force of the wind so that snow drifts 
in to a depth of several feet on the turf where this injury is evident

apt to occur on slopes than on the poorly drained, level areas where 
the ice-sheet type of injury predominates. The reason why this dis­
ease is so generally associated with heavy blankets of snow is not 
as yet clear. When drifts of snow finally clear away in spring it is 
frequently noticed that the grass is greener where it has been thus 
covered. This indicates that growth occurs beneath the snow but so 
far it has not been determined whether the damage due to the fungus 
in such areas is due to greater susceptibility of the plants when 
growing under this covering, or due solely to the prolonged moist 
condition maintained by the bank of melting snow. At times the 

April, 1927

73

disease is most prevalent on slopes with a southern exposure, as was 
the case shown in figure 6, but this is by no means a regular thing 
for in other places it is worse on a slope which faces north or in any 
other direction. Likewise there is no general rule as to its occurrence 
above or below a snow bank. The development of the fungus is de­
pendent on the presence of sufficient moisture on the grass during 
warm days in winter or early spring. This condition may prevail 
where the snow is gradually melting, where the water runs beneath 
the drift and in so doing acts as a tunneling agent which produces 
an air space frequently half an inch deep. During the day, as the

Fig. 8. Two types of winter injury. At the left is shown the light spots of grass killed by snow- 
mold. At the right is shown winter-kill where water collected in a slight depression during the 
winter. The snow-mold was active at the border of this winter-kill area and probably aided ma­
terially in the destruction of the grass throughout that portion of the green

sun shines through the thin layer of snow at the border of the drift, 
enough heat penetrates to raise the temperature several degrees in 
the cavity beneath. At night this roof of snow somewhat protects 
the turf from any slight freeze. The drip from above keeps the turf 
wet and conditions are thereby made ideal for the development of 
the fungus under this covering, so that as the snow bank recedes we 
find a condition such as that shown in figure 6. This probably 
accounts for the erroneous explanation offered by some observers 

74

April, 1927

that winter injury is due to ice acting as a lens to focus the rays of 
the sun on the turf beneath and to burn it in small spots, for the 
patches produced by the fungus might readily be mistaken for burns 
produced by a lens concentrating sunlight in a restricted area. At 
other times the injury occurs on a slope where the snow drift is 
above, as shown in figure 7. In such cases there is usually no melted 
cavity beneath the snow and therefore no possibility for any lens-like 
action on the turf. The fungus under these conditions usually de­
velops after the snow has left the turf but where there is a constant 
supply of water from the melting snow to keep the grass moist for 
some time.

Fig. 9. “A mulitude of evils.” A green where winter left the greenkeeper with a real problem, 
and incidently supplied us with a nice illustration for this article because the different types of 
winter injury are here combined in one photograph. This green was originally fescue but such 
injuries are rapidly converting it to clover and weeds. The light speckled appearance is due to 
damage produced by snow-mold. The larger irregular blotches are due chiefly to ice-sheets, although 
the snow-mold probably increased the injuries even there. At the far edge in the center is shown 
a mound from which a pronounced ridge projects into the green. The turf on the crest of the ridge 
dries out badly in the summer months. During the winter, snow is blown off it and the exposure to 
cold and drying wind results in a winter injury comparable to summer drying, as is here shown by 
the light color of the turf on this short ridge. This light area does not extend to the top of the 
mound, due to the fact that the upper portion was “scalped” by the mower and consequently no turf 
was there to be injured by winter exposure. Just why clubs still insist on trying to maintain turf 
of putting-green length on such abrupt ridges remains a mystery

This should not be confused with the injury due to water standing 
on the turf. In the case of the snow-mold, it is true, the turf must 
be wet but the injury in such a case is very distinct. Although a 
bank of snow may keep the soil in a large area soaked for many days 
the damage occurs only in patches where the fungus is active, 
whereas, in the ice-sheet injury all the grass in the low wet area is 
involved. This difference is clearly illustrated in the accompany­
ing illustrations.

April, 1927

75

Control of Snow-Mold Injury

The control of this disease has been a puzzle. The usual recom­
mendation of providing adequate surface drainage as a sure means 
for controlling all winter injury, obviously proves of no value what­
ever against this particular form. Many greenkeepers report that

they have been able to somewhat lessen the amount of injury by 
sweeping the affected areas just after the snow melts, while the 
slimy mass of fungus and decayed grass tissue is still spreading. 
This treatment is no doubt effective in breaking the coating over the 
grass and by so doing the as yet unaffected buds beneath are given 
a chance to dry more quickly and will probably escape and be able 

76

April, 1927

to develop and replace the injured grass as soon as the weather is 
suitable. This method is more effective where the grass is com­
paratively long, as on fairways or approaches. On greens where 
the turf is so short that this mat of decayed grass is far less dense 
there is some question as to whether such a practice is to be advised.
The question has been raised as to the possibility of controlling 
this disease by using grass resistant to its attacks. Unfortunately, 
there is no information available which can be relied on to answer 
this question. It will attack practically all of the northern turf 
grasses, but some species and strains are -unquestionably more re­
sistant than others. Redtop is more likely to be injured than blue­
grass in fairways. Fescue greens are generally more seriously 
affected than those of creeping bent. There seems to be some differ­
ence in resistance between the various strains of creeping bent 
planted vegetatively but observations are as yet insufficient to justify 
any general conclusions.

Since this injury is caused by a fungus, we naturally expect it 
to be controlled or at least checked by some fungicide, as is brown­
patch. The disease develops when snow is melting so any treatment 
with chemicals at the time it first appears' woM'd be a difficult pro­
cedure. It would be necessary to watch the greens constantly for a 
long period and to work on them when they are in a wet condition 
which would frequently result in far greater damage due to tramping 
than to the fungus. The most promising method of control is that 
of using a preventive treatment which can be applied the previous 
fall and which will serve to protect the greens throughout the winter. 
At Madison, Wis., we have found that corrosive sublimate will serve 
such a purpose. It is likely that any of the mercury combinations 
which have proven effective against brown-patch will prove equally 
effective against this injury, provided they are used in such quan­
tities as will give the equivalent amount of mercury. We prefer the 
corrosive sublimate for the reasons that it is cheaper, it can be used 
as a combination worm eradicator and fungicide and the quantity 
required for this purpose is harmless to turf when applied during the 
fall months. In figure 10 is shown a green where corrosive sublimate 
was used at different rates. One section received 2 ounces and 
another 3 ounces per 1,000 square feet. These applications were 
made the first week in October of 1926, the disease developed on this 
green in late February and early March of 1927. Although the dis­
ease was generally distributed over all the Untreated portions of the 
green, there was no sign of spotting on the areas treated with either 
the 2 or 3 ounces of corrosive sublimate per 1,000 square feet. On 
another 1,000 square feet area on the same green one ounce of corro­
sive sublimate was applied the same day that these heavier appli­
cations were made. This lighter treatment greatly checked the dis­
ease but there was a scattering of slightly infected patches which 
indicated that this amount was somewhat too light. The two or three 
ounces per 1,000 square feet are much more effective in bringing up 
earthworms so the heavier applications are doubly advisable. The 
cost of the treatment is not excessive, especially in its double capacity 
and is recommended for trial on greens which from past experiences 
have proven to be subject to attacks of snow-mold. It is apparent 
that this chemical is not to be expected to serve as a means for con­
trolling or even checking the winter injury caused by ice-sheets.

April, 1927

77

Care of Bermuda Putting Greens
By Dr. Thomas P. Hinman, Atlanta, Ga.

It is generally recognized that there are two distinct methods 
of handling Bermuda putting greens; one, known as the “starvation 
method,” in which no water is used except the natural rainfall and 
little or no fertilizer applied. In the other method, which I believe 
is the correct one, fertilizer is used and also artificial watering to 
supplement the rainfall. Having used .and observed both methods, I 
feel that I am in a position to pass on my observation and experience 
which, in a small way, may be a help to those who have the same 
problems to solve.

In our immediate section, the playing season on Bermuda lasts 
only about five months, beginning from the first to the fifteenth of 
June and lasting until about the fifteenth of November to the first 
of December when the frost kills the Bermuda. As playing is con­
tinuous throughout the year, we plant our winter greens around the 
fifteenth of September to the first of October. We have found that 
English perennial planted on a Bermuda base is very satisfac­
tory—that is, greens " are made double size and one-half used for 
summer play and one-lialf used for winter. In some instances there 
are two distinct greens for the same hole—one for summer, the other 
for winter play.

Bermuda that comes up after winter play has ceased, comes up 
rather scatteringly. Care must be taken of these greens during the 
summer so that in the fall all that is necessary is to cut the greens 
closely, scarify the surface with sharp rakes, clear off the debris 
that is left, by raking, sow them to English perennial rye at the 
rate of about 10 pounds to every thousand square feet, fertilize with 
bone meal and tankage—half and half—at the rate of about 75 
pounds per green. This will vary according to the size of the green 
—I am speaking now of a green containing an area of around 3,000 
square feet. A light topdressing to cover the seed is used, composed 
of woods earth, 50 percent; and sharp sand, 50 percent. It is some­
times wise to mix the fertilizer with the topdressing. Water im­
mediately after planting. Growth is very rapid, grass showing in 
about a week’s time.

When the grass has gotten high enough so that it begins to 
slightly droop, it needsz,cutting. The cutting is done with an ordinary 
lawn mower, being sure'that the blades are very sharp. The cutting 
is continued with this high-up mower until the green is ready to play. 
Then, the usual mowing is done, the green topdressed, or filled, and 
rolled.
• During the growing season it is not wise to do much topdressing, 
as it is liable to smother the young grass. If the green has a suffi­
cient Bermuda base, no topdressing is needed except just previous 
to play. Bone meal is used because it is very slow in giving up its 
ammonia and works particularly well on this type of grass.

In the "springtime, the Bermuda greens that have been laid aside 
during the winter should be prepared for summer play. In our sec­
tion, they are usually filled with Poa annua. It has been found that 
the best way to handle this situation is to take sharp hoes and skim 
off the surface, thus removing all foreign grass and weeds.

Bermuda greens nevei; come up uniformly; there are always a 

78 

April, 1927

number of dead spots. These should be scarified and sprigged with 
fresh Bermuda stolons, as well as the sowing of fresh Bermuda seed 
each year. The amount of seed needed each year will depend entirely 
on the green. As soon as the green gets a good start, applications 
of sulfate of ammonia at the rate of 6 pounds per 1,000 square feet 
should be made; these applications made preferably in a water solu­
tion. However, this fertilizing may be done by broadcasting and the 
water applied afterwards.

The Bermuda should never be allowed to get high and rank. 
Early cutting is advisable. The mower should be set low and the 
green clipped regularly. Early and constant cutting seems to cause 
the Bermuda to spread. An additional application of ammonium 
sulfate should be made at frequent intervals, depending on the growth 
of the particular green under consideration. A light application of 
fertilizer—about every two weeks—during the growing season is 
advisable*

It is not necessary to do any topdressing until a few days before 
the green is to be put in play. To get the best results with Bermuda 
greens it has been found, in a majority of instances, that a topdress­
ing should be made by using 50 percent of woods earth and 50 percent 
finely screened sharp sand, using this filling about every three weeks 
to a month.

To get a good Bermuda green the stolons should be kept buried, 
only the leaves of the grass showing through. Sometimes a Ber­
muda green can go as long as six weeks without topdressing, but this 
is unusual. Where giant Bermuda is used for putting greens more 
frequent dressings are necessary. In the so-called Atlanta strain, 
where the stolon is much smaller and the~leaf much finer and the 
growth much more compact, such frequent topdressing is not neces­
sary.

Poa Bulbosa
By H. L. Westover and O. B. Fitts

The Green Section, in cooperation with the U. S. Department of 
Agriculture, has been experimenting with Poa bulbosa at the Arling­
ton Turf Garden for several years. Little has been written about this 
grass as the results of the experiments thus far have not been such 
as to warrant very definite conclusions regarding its possibilities for 
putting green purposes. However recent press publicity has resulted 
in so many inquiries concerning the value of the grass for winter 
putting greens that a short article giving such information as we 
have regarding the grass should be timely.

Poa bulbosa is a bluegrass, the underground stems of which are 
true bulbs about the size of a grain of wheat. The leaves are fine 
and of a bright green color. At Arlington Farm it begins to grow 
about October 1 and remains green until May 1, when it dies down. 
For this reason it is often spoken of as a winter annual, though it is 
in reality a perennial since the bulbs remain dormant during the 
summer, sending up new shoots in the fall. The grass seldom grows 
to a height of more than three inches until in April when it sends up 
scattering seed stalks about twelve inches in height. Most of the 

April, 1927

79

panicles are normal in the Eastern States except that they produce 
no viable seed. In some cases, especially on the Pacific Coast, the 
spikelets are proliferous, small bulblets developing in the seed heads. 
The underground bulbs multiply about ten to fifteen fold per annum 
at Arlington farm and are known to retain their vitality for a year or 
more when stored in a warm, dry room. The grass is easily propa­
gated by planting the bulbs produced underground or the bulblets 
produced above ground. The bulblets, while much smaller than the 
underground bulbs, apparently produce just as vigorous plants.

Poa bulbosa is a native of Europe. The grass has been established 
in different sections of this country for fifteen years or more, though 
it was not identified until 1916. Just when and how it was intro-

Fig. 1. Poa bulbosa growing in dormant Bermuda turf on the right contrasted with dormant 
Bermuda turf on the left.

duced is not known. It has been established in the lawn of the Cap­
ital Square at Richmond, Va., for many years where it was brought 
to the attention of the U. S. Department of Agriculture in June, 1915, 
and was positively identified in February, 1916. Since that time Pon 
bulbosa has been found growing in relatively large areas in Wash­
ington, Oregon and southern California, and in smallei areas in the 
vicinity of Middletown, Conn., and Virginia Beach and Ashland, Va. 
In 1915 a small quantity of the bulbs from the lawn at Richmond, 
Va., were held in the Forage Crop office of the U. S. Depaitment of 
Agriculture at Washington, D. C., for a year or more. In the fall of 
1916 these dry bulbs were planted in a plot at the Arlington Turf 
Garden and produced a fairly good stand of grass the first year.

80

April, 1927

The stand was much thicker the second year, however, and the third 
year a very dense turf developed. Regardless of the fact that a con­
siderable quantity of bulbs have been harvested each spring since 
1922, this thick, uniform stand has been maintained to date. In 1926 
some of the bulblets were harvested on the Pacific Coast and for the 
first time offered for sale.

Wherever Poa bulbosa has been observed under turf conditions it 
has shown conclusive evidence of its value as a winter grass for fair­
ways and lawns. In combination with Bermuda it furnishes a turf 
that is green throughout the greater part of the year. In the vicinity 
of Washington, D. C., Poa bulbosa begins growing about October 1, 
which is about the time the Bermuda begins to turn brown, and I'e-

Fig. 2. A good lie on Poa bulbosa.

mains green until May 1, which is usually about two weeks before 
the Bermuda starts to grow. This lapse of two weeks is the only 
time during the year that the turf is really unsightly in appearance, 
whereas Bermuda, growing alone, is brown or straw colored from 
October 1 to May 15, and where Poa bulbosa is grown alone the 
ground is bare from May 1 to October 1. The accompanying photo­
graph (Fig. 1) shows the difference during the winter months be­
tween the combination of these two grasses and Bermuda alone.

The Bermuda does not seem to interfere in the least with the 
growth and durability of Poa bulbosa, and it is doubtful if the latter 
will interfere with the Bermuda where conditions are favorable for 
Bermuda. At Arlington Farm, where the two have been growing 
in combination for several years, the Bermuda has thinned out con­

April, 1927

81

siderably. This, however, is not regarded as a fair test since Arling­
ton Farm is in the extreme northern range of Bermuda grass, where 
it is often injured by low temperatures during the winter. Under 
such conditions the apparent lack of endurance of the Bermuda turf 
can not be attributed entirely to the Poa bulbosa. A valuable charac­
teristic of this grass so far as fairways and lawns are concerned is 
its dwarf habit of growth, eliminating the necessity of mowing 
during the winter months as it seldom attains a height of more than 
three inches. The turf is usually dense enough to provide a good lie
for the ball on fairways as shown in Fig. 2.

We have no knowl­
edge of this grass hav­
ing been tried out 
under turf conditions 
any farther south 
than Richmond, Va., 
but there is no appar­
ent reason why it 
should not grow suc­
cessfully on fairways 
in most parts of the 
southeast. Recently 
experiments have been 
started in different 
sections of the South 
and it is hoped that 
more conclusive infor­
mation will be avail­
able in the near fu­
ture.

At Arlington Farm 
close cutting of Poa 
bulbosa which would 
be necessary under ac­
tual putting green 
conditions, has thus 
far been rather dis­
couraging. We have 
as yet been unable to 
produce a satisfactory 
putting turf with this 
grass as it produces a 
rather long stem be­
tween the surface of 
the ground and the 
leaves (Fig. 3) and 
when cut closely enough to provide a putting surface the foliage is 
practically all removed, leaving a stubble rather than a turf. This 
stubble is unsightly and not at all satisfactory to putt on. Further­
more, the grass is very slow to renew its growth after being cut 
closely; in fact it never has recovered from more than one mowing 
during the entire winter. This experience, of course, is limited to the 
Arlington Turf Garden and there is a possibility that under different 
conditions it may produce a satisfactory putting green surface. How-

Fig. 3. Natural size photograph showing characteristics of 
individual Poa bulbosa plants.

82

April, 1927

ever, based on our experience, we can not recommend this grass for 
putting greens.'

Poa bulbosa should be sown in the fall and if the bulblets are used 
the rate of sowing should be about 4 to 5 pounds per 1,000 square 
feet; if the underground bulbs are used a somewhat heavier rate is 
advised. The preparation of the soil for sowing Poa bulbosa should be 
similar to that for other grasses. Where it is to be sown on estab­
lished Bermuda grass turf, all that is necessary is to cut the Ber­
muda as closely as possible and rake or harrow lightly in order to 
loosen the surface, after which the bulbs or bulblets may be sown 
broadcast. The ground should then.be rolled and in case of a dry 
season an occasional sprinkling will be found beneficial until the grass 
becomes well established. Watering is not absolutely essential, how­
ever, as the bulblets will not start until moisture conditions are favor­
able. For this reason there is little danger of the plant starting and 
then being killed by drought.

QUESTIONS AND ANSWERS

All questions sent to the Green Section will be'answered in a letter 
to the writer as promptly as possible. The more interesting of these 
questions, with concise answers, will appear in this column each month. If 
your experience leads you to disagree with any answer given in this column, 
it is your privilege and duty to write to the Green Section.

While most of the answers are of general application, please bear in 
mind that each recommendation is intended specifically for the locality 
designated at the end of the question.

-.... ....  l„ . 

t - --------- :----------- 1 r-1 

. — j.
1. Improving sandy fairway soil; growing rye for soil improve­
ment.—We are preparing to build the last four holes of our 18-hole 
course. The area is about 15 acres, which were covered with a sparse 
growth of scrub-pine and scrub-oak. The land is extremely sandy. 
There is a top layer of about 1^2 inches of black sand produced, no 
doubt, by the decomposition of vegetation over a period of years, but 
when plowed to a depth of about 4 inches, which was necessary in 
order to dispose of the pine needles and smooth and level the land, 
this black sand was turned under and pure sand brought to the sur­
face. Loam is scarce and expensive here, costing about $3 per cubic 
yard delivered. Stable dressing can be obtained only in small quan­
tities and is also very expensive. Can you suggest some inexpensive 
method of fertilizing this area? It has been suggested that we grow 
a crop of rye on it in the spring, to be turned under as soon as suffi­
ciently grown, thereby getting some organic matter into the soil, and 
then in early September to seed the land with equal proportions of 
red fescue and redtop. (Massachusetts.) 

Answer.—If you can get a fair turf once started on your sandy soil 
you should be able to bring it later to good condition by fertilizing. 
If you have reason to believe that it would be unwise to sow your 
land until the soil is improved, and if you desire to seed the land this 
fall, we know of no other way by which you can bring your soil to 
a satisfactory condition than to add loam, and mushroom soil, or 
manure this spring. It is not likely that a crop of rye planted in 
the spring would make sufficient growth by early summer to permit 
you by turning it under to add any appreciable amount of humus to 

.

April, 1927

83

your soil. In order to become of any value, the rye would have to 
be turned under so early in the season as to permit it to rot and 
give the soil time to settle so that a firm seed bed could be established 
by early September. Rye sown in the fall, however, may be ex­
pected to make sufficient growth by the following spring to permit 
being turned under to some advantage. As to sowing your fairways 
with red fescue and redtop in equal proportions, we do not believe 
either of these grasses will give you a permanent turf. Under the 
conditions you describe, your best fairway grass should be Rhode 
Island bent. Although Rhode Island bent seed costs more per 
pound than red fescue, the seed is much smaller, and you would 
therefore require considerably less seed, and even if sown in mix­
ture with redtop would give you a permanent turf.

2. Value and use of pig manure.—We have available a large 
quantity of pig manure. Is it suitable for composting, and if so, 
how should it be treated? Can it be deodorized without destroying 
its value if used in compost heaps? (New York.)

Answer.—We consider pig manure as very good material to use 
in compost piles. The piles should be kept for a considerably longer 
period than in the case of cow manure, as the solid excrements of 
hogs decompose less rapidly than those of horses, cows, or sheep. 
There is a prejudice among farmers against the use of pig manure, 
but no real basis for this prejudice has ever been discovered. Prob­
ably the best preservatives to use in connection with the composting 
of manure, and both of which have more or less of a deodorizing 
effect, are gypsum and floats, the latter being raw rock phosphate 
finely ground. If either of these substances is used it should be used 
at the rate of 4 pounds to 100 pounds of manure.

3. Improving bent greens that are fluffy.—Two of our greens 
were planted from bent stolons last fall, but unfortunately the green­
keeper let them get away from him so that the mower could not cut 
the grass at all. The result was that the greens were practically 
hopeless; although soft and comfortable to walk on, they were im­
possible as putting surfaces, being neither true nor fast enough. 
Personally I think the turf is too thick and matted and far too long, 
and our problem is to get it into condition where it can be properly 
cut with a mower and kept so. (New York.)

Answer.—You have no remedy except to rake up and then cut 
away the tall, matted growth. When this is once done, by top­
dressing every month and cutting closely each day you can get a 
good putting surface again. Your greens will look bad for a time, 
of course, but they can be kept in good condition only in the manner 
we have outlined.

4. Poultry manure as a fertilizer.—What in your opinion is the 

value of poultry manure as a fertilizer? (Pennsylvania.)

Answer.—In our experiments we have found pulverized poultry 
manure to be a very quickly acting and effective fertilizer. For bent 
putting greens, however, our best results so far have been obtained 
with ammonium sulfate and ammonium phosphate.

Since the publication in the October Bulletin of results in con­
trolling brown-patch with calomel, questions have been received as 
to whether the Green Section definitely recommended that clubs shift 
entirely to this chemical as a means for controlling brown-patch. 
Questions are also asked as to where calomel may be purchased and 
in what form it should be used.

As far as we know, calomel has been used against brown-patch 
only experimentally so we hesitate to recommend it in any dogmatic 
way. We prefer the policy of using results of experiments at Arling­
ton simply as indicators. There a large number of chemicals and 
various methods may be tested, the great majority of which are 
obviously worthless and therefore discarded. An occasional one 
shows promise and is repeatedly tested until its worth is proven 
under the conditions obtaining at the Turf Garden. Under our pres­
ent system we are unable to carry the tests further. The suggestion 
is then passed on to clubs through The Bulletin. Differences in 
soil or climate may produce results on some courses quite different 
from those observed at the Turf Garden. Past experiences, however, 
indicate that in the majority of cases experimental results at Arling­
ton may be regarded as safe criteria for a large proportion of the 
courses in the region where bent is used. At present the calomel 
method for checking’ brown-patch is at the stage of being “passed on 
to clubs.” A number have promised to test this chemical and report 
results as soon as the disease appears during the coming season. We 
will then feel sufficiently informed to make a more general recom­
mendation. For the benefit of those who purchase supplies well in 
advance we advise that chemicals for the control of brown-patch be 
purchased in quantities sufficient only for the first emergency. Later, 
if calomel continues to prove as effective as the more expensive mer­
cury compounds, clubs will have time to shift to calomel for later 
applications. Certain clubs which have followed previous experi­
ments at Arlington' and found that results on their courses closely 
correspond with those at Arlington may feel more confident in using 
calomel extensively and may be able to effect a considerable saving 
in cost of material during the summer.

Calomel is used for human medicinal purposes and may be pur­
chased at any drug store. In bulk it may be obtained from any of 
the large chemical houses, for since not a patented product it is not 
controlled by any one company. It is produced in the crystalline 
form but is usually sold as a fine powder. For brown-patch control 
it should be bought only in the powdered form.