P U B L I S H ED IN F E B R U A R Y, M A R C H, APRIL, A U G U ST A ND SEPTEMBER BY O. M. SCOTT 8c SONS CO. MARYSVILLE, O H IO Sixteenth Year Number 75 L A WN A NEW WEED-WORSE THAN IT SOUNDS P E N N Y W O RT the case of Lawn Pennywort they have more of a glossy sheen. That is possibly the first noticeable distinction. Another is the fact that Lawn Pennywort makes a much denser growth, with leaves closer together and a coverage that is practically solid as shown by the illustration. Wher- ever Lawn Pennywort really thrives there is very little growth of grass or other weeds and no bare ground can be seen. Ground Ivy makes a rank growth but has the characteristic of intertwining with grass and weeds. The slender stems of the Pennywort creep underground slightly below the sur- face as well as on top of the ground. Small tufts of fibrous roots occur at the nodes, which are distributed at intervals on the creeping stems. This mass of stems and DURING the last year, several unusual weed specimens reached us for iden- tification. A cursory examination labeled them as Ground Ivy but it developed that they were something more objectionable, namely LAWN PENNYWORT, (hydro- cotyle rotundifolia). The characteristics and habit of growth of Lawn Pennywort and Ground Ivy are indeed similar. Both are low growing, creeping perennials. The leaves are alike, being rounded or kidney shaped, scallop toothed and varying in size from % to % inch in diameter. The largest of the leaves barely approach the size of a dime while the smaller and more predominant leaves are hardly a third of that. The leaves of Ground Ivy and Lawn Pennywort are generally smooth, but in Typical infestation of Lawn Pennywort. Note thick growth and small size of leaves as compared to the tree leaf and grass blades. C O P Y R I G HT BY O. M. SCOTT & S O NS CO. wMbOiHtb roots enables the plant to live through the winter. Aside from the glossy leaves of Lawn Pennywort there is a difference in flower- ing. Ground Ivy blossoms vary in color from pale to deep purple, while Lawn Pennywort blooms five small white petals. in a cluster of thrive Both weeds in moist places, Ground Ivy usually only in shaded spots, Pennywort in sun or shade. For some rea- son the latter is often found in green- houses thriving in the shade of benches. Another weed that may be mistaken for Lawn Pennywort because of similarity in names is Moneywort. It also has a low growing, vining habit as described in LAWN CARE N O. 6 5. Distribution Lawn Pennywort is a member of the parsley family and as such it is sometimes in ornamental horticulture as a used ground cover. It has not long been rec- ognized as a pest in turf, the earliest ref- erence appearing in the literature in about 1921. There it was reported as infesting the putting greens of one of the Washing- ton, D. C., golf courses, and strangely enough it was in the District that most lawn infestations were reported last year. There are reports of scattered develop- ment of Lawn Pennywort throughout the Spraying test plots of Lawn Pennywort with various chemicals to find an effective control. By U. S. Department of Agriculture, in effort Washington, D. C. Eastern Seaboard south of New York and as far west as Louisville. Fortunately its present distribution is limited but Lawn Pennywort is spreading and may develop into one of the worst lawn pests. In fact, one LAWN CARE reader describes it as a menace comparable to Japanese Beetles. Because of its pernicious habits, lawn own- ers in other parts of the country may well be on the lookout for it. If small patches of Lawn Pennywort are discovered they should be removed and destroyed as otherwise the spread may be rapid. The creeping root stalks are con- stantly reaching out and seeds are carried about the lawn by wind or on the soles of shoes. Control Not Easy Because Lawn Pennywort has not as yet become very common, not much experi- mental work on its control is reported. Most efforts at eradication have been made by owners of badly infested lawns. One attempt of a Washington, D. C., resident was to roll up the sod from his lawn which had become practically all Pennywort. He had this hauled away and the area reseeded. Apparently he did not go deep enough to get the roots because the next year his lawn was again a solid mass of this pesky growth. Various chemicals have been tried but up to now none has been successful. Tests are being continued in Washington by the Green Section and the Department of Agriculture. Quite a number of new treat- ments were made last fall, but the results will not be known until summer. In the meantime the advice is to cut out any patches of Lawn Pennywort before they can spread far. The soil should be removed to a depth of 154 or 2 inches and the plants burned or otherwise destroyed. The root stalks or seeds of removed plants must not be allowed to contaminate other areas. Since Pennywort is a moisture loving plant, its growth is encouraged by exces- sive summer watering. An infested lawn should therefore be kept slightly on the dry side if possible. New Idea for Watering Terraces Someone should have thought of this before. Perhaps they have, but Mr. Albert C. Nordlich, R. D. 10, Cincinnati, Ohio, tried it and is most encouraged about the results. He realizes, of course, it will take a couple of dry summers to tell the whole story. that We have reproduced here Mr. Nord- lich's drawing and this is his comment: "On the top of this terrace I am going to dig a trench its full length. It will be 10 inches deep and wide enough to receive a 6 inch unglazed tile. These tiles will be placed with one-fourth inch joints. The two end tiles will have flat stones at the openings to keep soil from washing. I shall run these tiles as shown in the illus- tration to a water faucet. My idea is that by filling these tiles with water every day or so, it will filter down the terrace and through capillary attraction water the grass at the roots. "I can also put fertilizer in these tiles. terrace "I am planning to build this with new soil and seed." That was last summer. Recently we checked up with Mr. Nordlich to see what he now thinks of his system. This is his reply: "My terrace was completely rejuvenated and the watering system installed. There is a stand of young grass but the supreme test will come in July and fine August. going to be very satisfactory." I am confident the results are We shall report again on this project in September L A WN CARE and if possible get a photograph of the terrace. Dogs vs. Lawns A m o ng the readers of LAWN CARE are several types of people. For example, there are those who like dogs and tolerate any- thing they do; second, those who like dogs but realize it is hard for a nice lawn and dogs to get along amicably and, third, those who don't like dogs and the dam- age they do to turf still less. In recent years dog letters have increased in num- ber by leaps and bounds. "My grass looked beautiful," writes a distressed customer, "until several dogs began using it for a playground. Now it's a mess. What can I do?" the "burn" resulting Even those who own prize dogs, espe- cially females, ask what can be done to offset from dogs selecting the most conspicuous part of a lawn to pass their urine. The question is asked as to what can be used to neu- tralize the acid. likely that anything would be effective, unless possibly someone was on the "alert" all the time to apply the antidote. It doesn't seem In our own judgment, as long as dogs lawns will are allowed free circulation, shrubbery and Victory suffer—as will Gardens. Various sprays are available which, when applied to shrubbery, are said to repel dogs because they do not like the odor. Following the first heavy rain, the effect would presumably be lost. An electrically charged wire or fence may be put around some choice bit of planting as a safeguard but the time as well as the cost in case of a large area would render this idea impracticable. Someone has suggested Tobacco Dust as a top- dressing, claiming it to be a dog repellant. Here again the canines would be back after the material had disintegrated. Has anyone a solution other than phon- ing the Mayor? Report Effects of Salt on Grass lasting damage A LAWN CARE reader introduced the thought recently that salt used on icy side- later prove to have done walks would some to grass adjacent to such walks. This question was raised in Bulletin No. 74 in spite of the fact that some years ago an Oregon resident claimed to be using applications of salt to stimulate grass and discourage weeds. Experiment Station authorities countered with the statement that not enough salt was being used to do any harm, but that the man was just out his time as far as benefits were concerned. The following observations came in response to our recent request for com- ments: the lawn "I have failed to find salt harmful to my lawn and have used it on icy sidewalks for seven or eight years. It is easier to repair I might add that mine is a beautiful Scott Creeping Bent Lawn, too." Thanks are due to Mr. George P. Ruemmler, Execu- tive of The Cupples Company, St. Louis, Missouri, for that statement. than broken bones. in this to affect Says Miss Elsie Hays of Spencer, Iowa: seem lawns "Salt does not territory, but actually adversely aids the growth of grass. It acts as a soil amendment. The the insoluble potassium in the soil and makes it available [Do other chemists agree?] The only bad effect is the deterioration of concrete sidewalks. Salt seems to cause the concrete to slough off." for plant use. replaces sodium A salt salesman of 35 years' experience, Mr. Adolph Eccardt of Brooklyn, New York, says if properly applied the salt won't get onto the grass. The brine, he says, creeps along the walk and not enough gets into the grass to be harmful. He cites the Park Departments of all large cities are using salt on icy walks to pre- vent accidents with no lasting damage being done to lawn areas. Do others wish to say something on this subject? — a— SIRS: I have L A WN CARE No. 73, in which you have one excellent article, "Keeping Up a Lawn the second page under in These Times." On "Mowing" you advise to catch or rake up the clippings. the other for many years, one seeded The Agronomy Department has had two areas to in grass now to Colonial Kentucky bluegrass and bent grass. In these there are many small plots variously fertilized and otherwise treated. In each these grass there are duplicate plots clipped all years and the ground. the same fertilizer applica- Adjacent plots with tions have had the clippings caught up and removed. the clippings let fall on The outcome is that where the clippings are left the grass is far better, the turf is more like a carpet and the grass withstands dry weather immeasurably better. This grass left on the area has not proved to be unsighdy or undesirable in any way. I pursue the same method on my own lawn. While it is not a show lawn, it has been quite satisfactory and has a better appearance than similar lawns from which the grass is removed. If one let his grass go too long without clip- few ping, days. However, return of nutrients has justified us in leaving the clippings, to and I do not hesitate leave they do not let the lawn go more than about a week without clipping when growth is active. the dry hay would be unsightly a the clippings, particularly to advise my friends the mulching and if the production of better Your firm is doing a good service in encour- I aging would not want to accept this idea. H E N RY DORSEY Professor of Agronomy The University of Connecticut lawns. Yet, Storrs, Conn. Professor Dorsey makes a good point but many LAWN CARE readers definitely feel that grass clippings are unsightly on the lawn. O. M. SCOTT & SONS CO. MAR Y S V I L LE • • O H IO EVERY PACKAGE OF SCOTTS LAWN SEED BEARS THIS TRADE-MARK AND IS SEALED FOR YOUR PROTECTION