P U B L I S H ED IN F E B R U A R Y, M A R C H, A P R I L, A U G U ST A ND S E P T E M B ER BY O. M. S C O TT & S O NS C O. M A R Y S V I L L E, O H IO Sixteenth Year Number 77 W I N T ER D A M A GE TO L A W NS IN THESE nice fall days it is difficult to write about what may come in the dreary days of winter. Even so, after the severe damage to lawns during last winter it seems advisable to discuss what may happen in the next season of snow and ice. Much of the injury during cold weather is due to causes beyond control such as extreme cold with high winds at a time when grass is without the protection of a blanket of snow. Frequent freezing and thawing is especially damaging in heavy and poorly drained soils. In some winters a fungus may attack grass and cause a harmful disease called Snowmold. Turf damage from Snowmold was quite gen- erally reported last winter. Most attacks of Snowmold are thought Fusarium to be caused by nivali. This is dormant in soils most of the time but may become active when the the fungus condition is favorable for its development, namely, temperature just above freezing in combination with excess moisture. Quite often snow is associated with these conditions as when a soft snow falls on unfrozen ground or during melting of a heavy snow. In spite of the inference of the name, the disease Snowmold may appear even though no snow is present. In the early stages of the disease the fungus may appear as a thick cottony growth, covering definite but irregularly shaped patches. When wet the patches have a slimy feel. As the fungus grows it enters the grass blades and stems to break down the cell structure. As the grass dries it takes on a dirty, whitish-gray color. It is not so difficult to distinguish between the damage of Snowmold and other winter kill. In the latter case large, definite areas will be brown and dead Results of an attack of Snowmold on putting green turf. Note various sizes of affected spots compared to the lead pencil. Photos courtesy Green Section U. S. Golf Association. COPYRIGHT BY O. M. SCOTT & SONS CO, it looking, whereas with Snowmold is possible to pick out distinct patches even though there may be so many of these that they merge into large areas. Further- more, the appearance of grass after an attack of Snowmold is a distinct bleached- out pallor, totally unlike anything else. Grass damaged by being walked on when it is frozen and not protected by snow has somewhat the appearance of Snowmold injury. However, it is usually possible to distinguish the pattern of foot- print damage. Any traffic over grass in winter should be avoided if possible. Snowmold does not always destroy what it attacks. Sometimes only the topgrowth is affected, other times the roots are killed and recovery is impossible. Most reports of severe Snowmold dam- age come from the more northerly lati- tudes, particularly from Boston west to Cleveland, Chicago, and up to Minneapo- lis. In some years there is considerable damage much farther south, as far as Vir- ginia and Kentucky. Such was the case in the winter of 1942-43 when damage was pretty general from those states north. Injury of Snowmold is most apt to show up after a thaw in the late winter. As snow is melting a good condition for the disease is present since under the snow there will be a surplus of water and a temperature slightly above freezing. Checking the Disease likelihood of severe damage As far as the average lawn is concerned, the is so remote as to preclude any necessity of worrying about it. However, where past experience has shown that there is a con- dition favorable for Snowmold, it may be wise to take preventive measures. Certain mercurial fungicides such as used on putting greens for the control of Brown Patch, have been found effective against the Snowmold fungus. A good is one ounce of Corrosive combination Sublimate with two ounces Calomel applied to 1000 square feet. However, these materials are difficult to obtain in war times. So are the usual commercial mercury preparations such as Calo-Clor, recedes As snow the slope, Snowmold damage becomes apparent. It gets progressively worse level because of greater from toward lower excess moisture. Semesan and Nu-Green. In the search for substitutes the Bayer -Semesan Company has produced a new fungicide known as Thiosan. This has been found effective as a preventive in controlling Snowmold as well as Brown Patch when used at the rate recommended by the manufacturers— about three ounces to the 1000 square feet. If a lawn area is to be treated, the fun- gicide should be applied in late fall or early winter, preferably before any heavy snows. One treatment should suffice. It should be put on with a pressure sprayer or sprinkling can, or mixed with dry sand or soil and spread by hand. Those not having spraying equipment can get Scotts Turf Fungicide, mixed with a dry carrier for easy hand application. It is not necessary to treat the whole of a large lawn, but only those sections where conditions are favorable for Snowmold, as for example, the bottom of a slope where there is apt to be a surplus of water result- ing from snow melting on higher ground. The same may be true of areas where large piles of snow and ice are thrown up in cleaning walks and drives. These should be avoided If grass is covered with manure, straw or other mulch materials, it is more apt to suffer if possible. attacks of Snowmold because such cover- ings retain excess moisture. Repairing the Injury revive or the plants will is necessary. The severity of attack will determine if whether reseeding In either event the affected spots should be brushed or raked in early spring to remove the dead growth. Then examine the stems and roots to see if new growth is starting. If not, seed as early as possible and topdress lightly with screened soil. — — • Problems of Salt vs. Lawns This innocent subject aroused more comment than anticipated. The general summary should read like this: An over- dose of salt will kill the grass while a light dose will do no harm—might even have some slight benefit. the grass along The whole question arose when a reader of L A WN CARE asked about using salt on the sidewalks in icy weather being fearful that the walks might not live to tell the story. The discussion became complicated by introduction of evidence to the effect that salt was detri- mental to the cement so should not be used, regardless of whether or not grass figured in the argument. Since the release of L A WN CARE N O. 75 which brought up the salt question, these interesting comments have been received. We feel they do a good job of wringing the subject dry and that folks with lawns may use salt this winter or not use salt, depending on which side of the debate checks with their own experience. Chicago, Illinois—"Because of the un- usual amount of ice this winter, several times I had to put a small amount of rock the cover of my underground salt on garbage can. three-inch band of dead grass around this cover." I now have a Toluca, Illinois—"I read in a catalog that salt would kill Dandelions but would not harm the grass. I tried it last fall on a small area of lawn and now it is as dead and barren as the road." Cicero, old gardener told me that the only type of vegetation that Illinois—"An was benefited by salt, at least not harmed by it, was asparagus. He uses it to keep the weeds out of his asparagus bed. I have found salt definitely harmful to grass." Chicago, Mansfield, Ohio—"Please explain why the grass is so healthy growing between the flagstone walk where I used more salt this year than usual." Illinois—"As a retired mail man with 32 years' experience on icy walks, I believe I am qualified to say something on the subject. In my estima- tion, for slipping, salt is the worst thing you can use for this reason—when going across a salted walk a coating of water forms on the soles and acts like grease when going from a salted walk onto an unsalted one. I would suggest using sand. It will not harm injure concrete and is not messy like ashes and will not puncture rubber footwear like unsieved ashes. A bucket of sand gath- ered in wintertime." in summertime is a blessing lawn nor the Baltimore, Maryland—"During a violent storm our lawn was covered entirely by a high tide. Everyone felt sorry for us, believing we would lose our grass. As a matter of fact, the salt water was on the lawn just long enough to fertilize it. The result was that last summer we had the best grass in many years. Salt water on grass is like a good many medicines—the proper amount for the proper duration is beneficial but too much is injurious, even to the extent of killing." Detroit9 Michigan—"If salt is used once or twice sparingly, the grass is not harmed, but two winters ago I used salt about five times during the winter and when spring came I discovered the lawn was destroyed for a distance of 6 to 8 inches from the walk." Rochester, New York—"This is the first year that I have used salt, due to the fact that we have probably had more trouble with our sidewalks than ever before. Most of the ice and snow had to be carried about five feet and was all placed on a pile on the lawn. The grass at this spot is completely burned and I can see no other reason than the salt." in excess. Try Here is an interesting unsigned obser- vation: "Potash will kill grass quicker than salt when used it some time. Salt is good on some soils. In fact the so-called Potash imported from Geneva during the first 50 years contained more salt than Potash. Not until Ameri- can Potash was put on the market did farmers get any Potash with less than 20% salt. Fifty percent KzO (Muriate) is 80% Muriate (KC1) and 20% salt. Sixty-two percent contains about two per- cent salt." ice. Cicero, Illinois—"My experience starts about four years ago. In the winter I had a downspout freeze up which covered the sidewalk with I used rock salt to thaw out the downspout and naturally some of it was spread on the walk. This ice I scraped ofi and threw on my lawn, also some of it got on a Paniculata Clema- tis which I had growing under gutter. Both the Clematis suf- fered—the Clematis died and the lawn was very poor for two years." lawn and the A Few D og Lovers Snap Back lovers, The dog bulletin evoked much com- ment. All but a handful of readers, even intense dog the various reader recommendations good-naturedly. So far two readers of five hundred thou- sand circulation thought we were spread- ing a cruelty campaign. took The general consensus of opinion was that whether or not you or your neighbor have a dog, he should be restrained from being destructive, especially is some method of harmless discipline. there if A few folks wanted their neighbors to have the bulletin; others suggested that it ought to get into every newspaper in the country, while many said it gave them the heartiest chuckle in years. The Scott Publications Lawn Care—Subjects featured vious bulletins include: 1928 Plantain, Sodium Chlorate. 1929 Compost, Moss, Web Worms, phate, Buckhorn. in pre- Iron Sul- 1930. Ground Ivy, Yarrow, Earthworms, Heal- All, Ants. 1931 Speedwell, Creeping Knotweed. Buttercup, Moles, 1932 Sheep Sorrel, Quackgrass, Spurge, Trefoil, Goosegrass. 1933 Nimble Will, Knawel, Terraces, Shepherd's Purse, Ground Covers. 1934 Sedge, Purslane, Spring Seeding, Dande- lions, Summer Feeding. 1935 Peppergrass, Shade, Summer Injury. 1936 Clover, Poa Annua, Henbit, Fall Seeding, Foxtail. 1937 Honeycombed Soil, Grubs, Orchard Grass, Soils, Turf Diseases. 1938 Liming, Dandelions, Chinch Bugs, Burlap Cover, Wild Garlic. 1939 Chickweed, Mowing, Dandelions, Fall Seed- ing, Poison Ivy. 1940 Spring Program, Organic Matter, Watering, Vitamins. 1941 Winter Afiects Grass, Fertilizing, Money- wort, Mallow, Weed Control. 1942 Care of Tools, Tree Feeding, Crabgrass, Devil's Paint Brush. 1943 Spring Lawn Program, Gardening for Vic- tory, Lawn Pennywort, Dogs Beware. Paper Bound File—25c postage paid including all above bulletins. Loose Leaf Binder—$1.00 postage paid, all L A WN CARE issues to date and room for several years' future bulletins. Good Lawns—That amateur gardener's guide to better lawns. Contains a com- plete outline for building new lawns and improving old ones. Free. Bent Lawns—Illustrated new edition. Tells about the most beautiful of all lawn grasses—Scotts Creeping Bent. Care Of Bent Grass—Describing the best maintenance practices for pure Bent Lawns. O. M. S C O TT & S O NS CO. M AR YS V IL L E • • O H IO EVERY PACKAGE OF SCOTTS L A WN SEED BEARS THIS TRADE-MARK A ND IS SEALED FOR YOUR PROTECTION A A