PIONEER seedsman O M Scott was a man of vision. He also had a hatred of weeds that was unusual in his day and would still be. Although he long since has left this world, his antipathy toward weeds has continued as a strong force in the business left for his sons to carry on. During the last 25 years one weed in particular has been annoying to the Scotts force — Crabgrass, also called Watergrass, Summer Grass, Fall Grass (Digitaria Finger Grass and Wiregrass sanguinalis; D. ischaemum). Here is a It weed has no virtues, no the seed trade—which is often innocently blamed for its depredations. low-down sneak. in friends is a that Something good can be said about almost every other weed. The dan- 2 3 rd Y e ar PUBLISHED FIVE TIMES YEARLY FOR LAWNTHUSIASTS THE U N D O I NG OF CRABGRASS taken Its delion makes good salad greens. sprightly blossom individually is not unattractive, but in mass they look bad, especially in your own yard. Other weeds have herbal or medicinal value. Some occupy ground that would otherwise be barren, reducing erosion. thus But Crabgrass doesn't even do that. It is a lazy variety, hardly stirring from the soil until the sun gets the ground cozily warm. Even then Crabgrass really won't get up and go until it's so hot that the desirable grasses subside. As they go into their summer siesta the real Crabgrass invasion develops. With the first adversity of a fall frost Crabgrass gives up. The plant dies, but its remains show up as ugly brown patches through the entire win- ter. Before that it will have insured a C o l or P h o to by Scotts L a wn R e s e a r ch C r a b g r a ss h as g r o wn t he to s m o t h er to m a t u r i ty t u r f. B e a u t i f ul t u rf b e c a u se SCUTL s t o p p ed t he C r a b g r a s s. lawn suffers learned Not every for another year by dropping crop thousands of seeds to the earth. this fate because some folks have to keep the upper hand. They pluck the seedling Crabgrass plants or get rid of mature plants before they set seeds. Most lawn owners do not have the time, patience or inclination for cul- tural control of Crabgrass. It is the devastation wrought by Crabgrass in those that has bothered Scott people these many years. lawns I n s i d i o us b e g i n n i ng of a C r a b g r a ss in a g o od p i e ce of t u r f. S t o p p ed i n v a s i on in t h is s t a g e, C r a b g r a ss w i ll do l i t t le h a r m. Scotts Tried A to X the last During quarter-century Scotts Lawn Research has grasped every suggestion as to what to do about list of experimental Crabgrass. The chemicals starts with ammonium thio- cyanate, continues with borax, chlorate, di-nitro, fertilizer, ground glass, kero- sene, lead arsenate, mercury, oils, potas- sium, sodium arsenite, and on through the alphabet to xanthate. Other efforts involved shading, covering with tin cans and old magazines, freezing with dry ice, painting with dyes. In these 25 years there were years of hope. In fact so much that Scotts tests were carried on in South America and Guatemala to gain extra grow- ing seasons, but to no avail. In the winter of 1946, new hope appeared in a preliminary report on observations made at Rhode Island State College. Those in charge of work on turf noted that certain plots being treated for disease control were clear of Crabgrass. It happened that the fun- gicidal treatment carried a complex organic mercury as its active ingredient. Here was an indication that mercury in the right form might prove a differ- ential chemical for Crabgrass control. Toxicity W as O ne P r o b l em So far so good. But immediately the problem arose that concentrates of mer- cury were strongly poisonous. That T y p i c al a l l o w ed s u m m er m e ss l a te C r a b g r a ss to g r ow u n c h e c k e d. Seeds a re d e v e l- of o p i ng to set t he c r op f or f u t u re y e a r s. it out to rule seemed immediately because the feeling in the Scott organi- zation was that it was necessary to keep away from hazardous substances. Nevertheless, a series of trials was laid out. Results in 1947 were erratic but before the summer was over there was sufficient encouragement to justify large scale experiments except for the recurring problem of toxicity. The dilute sprays themselves were relatively harmless but the concentrate used to make the spray was not. It was then suggested that a dry formulation be tried, on the basis that a bulky carrier would result in such a grass control until the final question- naire at the end of the summer. Not everyone achieved good results. For one thing, questionable formula- tions were sent to some folks to double check that nothing was being over- looked. Then too, directions were not always followed. In some places heat and drouth killed Crabgrass as well as desirable varieties. But, by and large, the enthusiasm of these volunteer test- ers equalled or exceeded that of the Scott organization. SCUTL Is Its N a me That is only part of the story but from this work has emerged a dry compound called SCUTL. It subdues Crabgrass with little or no harm to desirable grasses. It is applied by hand or spreader the active Crabgrass season. in In country-wide tests SCUTL has proven effective on all species of Crab- grass, whether in Washington, D. C., (where it is jokingly called Washing- ton Bluegrass), southern California, Minnesota or Long Island. the dilute amount of toxic material as to be relatively safe. At first idea seemed preposterous and was almost dismissed with little thought. How- ever, stubbornness won out and a series of greenhouse studies was undertaken. The Scott research crew was spurred on by the knowledge that lawn owners were pleased to use dry materials so easily applied with a lawn spreader. It was no easy task to find the right dry carrier. It had to be relatively light in weight, fine but free from dust, absorptive, uniform in particle size. A select grade of vermiculite emerged after two years of trials as the substance meeting these requirements. Beginning with the 1948 Crabgrass season, many of the dry formulations were applied infested areas. Before that time several acres of Scotts testing grounds had been seeded to various species of Crabgrass to insure adequate experimental areas. to Crabgrass The Quest For S o m e t h i ng Better When the reports were in at the end of the season, it was obvious that here was something. But the research crew was not satisfied. Their results with the dry treatments were as good as the best spray program, but not better. And better they liad to be if a Scott Lawn Care product were to emerge. into the inert So day and night work continued until a unique method of solubilizing the chemicals was developed. This solu- then sprayed at controlled tion was temperatures carrier. After cooling and screening, the result was a product of good uniformity, chemically as well as physically. formulations and others were sent to a large list of volun- teer investigators for 1949 use on home lawns. They had previously agreed to apply the material identified simply as a "summer treatment." They had no idea of the purpose but made applica- tions and saw. None had a hint he was trying a Crab- superior reported what they These A w a lk o v er t he l a wn a nd t he j o b 's d o n e. I t 's an e a sy t r e a t m e n t. T wo s t o r i es in d o se of S C U TL t h is p i c t u r e: in ( 1) p a t c h es of l a te A u g u s t, w h i le d r a m a t ic e v i d e n ce of s e l e c t i v i ty of ( 2) d e s i r a b le g r a s s es t he c o n t r o l. l a r ge C r a b g r a ss k i l l ed by a r e m a in b r i g ht d o u b le g r e e n- H ow SCUTL Is Used is best to get rid JUNE-JULY.—It of Crabgrass as it is getting started and before it is smothering the lawn. Late June or July, when Crabgrass is about as pictured at the top of page 2, is a good starting time. One or two repeat treatments are advised at intervals of a week or ten days. This^ is necessary to catch plants missed the first time, also new plants. There is delayed germination of Crab- grass seeds throughout the summer so one application is really not enough. As Crabgrass plants die from the dose of SCUTL, they will naturally wither, turn brown and finally decay. This means some degree of discolora- tion, depending upon how extensively Crabgrass had taken over. AUGUST-SEPTEMBER.-If Crab- grass grows unchecked through mid- summer, it will make the heavy, rank growth as shown by the second picture required: Double in a week. on page 2. Then more drastic action treatment;, is repeated treatment would have stopped Crabgrass in the lawn pictured on this page before it did so much damage. rate July is a Since Crabgrass self-seeding annual, stopping its growth before seed is matured means a much smaller infestation next year. SCUTL is active only on vegetative growth, so it is all right to sow lawn seed immediately after use, if time and conditions are favorable to planting. is advantageous If Crabgrass control is delayed until late August or September, the use of SCUTL the fall It stops growth renovating program. of Crabgrass within a matter of hours after which lawn food and seed may be used to restore the lawn promptly. in ¿M&& O M SsudAmsw ¿incc 1870 cdt VYlwiyAvilk, Ohio & SONS CO 4 SCOTTS AND LAWN CARE ARE REGISTERED TRADE MARKS OF O M S C O TT & S O NS CO. 6 1 2 50