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 8t S O NS C O ., M A R Y S V I L L E, O H IO August 1932 F I F TH Y E AR Number 21 Y E L L OW TREFOIL MOST weeds have flourished this season but Yellow Trefoil or Black Medick has outdone itself. Speci- mens of this weed have come in for identification from almost every north- ern state and we are informed by sev- eral experiment stations that they have had the same experience. One authority says: "Yellow Trefoil seems to be prevalent all over the country this season. In 1928 we noticed it grow- ing in our golf fair- ways and this is the first year since that time it has put in its appearance." Once Used in Lawn Mixtures While Trefoil is not considered a nox- ious weed it doesn't belong in a lawn. Yet surprising it is to learn that Trefoil seed has in years past been used lawn mixtures as a substitute for White Clo- ver. Perhaps that is where this weed got its first start in lawns. At present it is found most frequently in the seed of farm crops such as Alfalfa, Sweet Clover and Red Clover. Stock does not object to it so on the farm Trefoil causes very little concern. in Yellow Blossom Easy Identification The illustration is handicapped be- cause of not being able to show the small clover-shaped yellow blossoms. They make this weed very easy to iden- tify. Trefoil is a member of the clover family and the small blossom, except for the color, is a miniature of White Clover. It is an an- nual and would be easy to destroy before the plants go to seed except t h ey grow very close on the ground and the mower is apt to miss them. is throughout the world in all temperate cli- mates. The plant it- self branches out and spreads in creeping fashion. The leaves are f i n e ly h a i r e d, rounded and slightly toother at the tips. The pods containing the seeds are thin skinned, kidney shaped and slightly twisted. Each pod contains just one seed. Its range that Seeds Resemble Alfalfa The seeds themselves are yellow and very much resemble alfalfa and sweet clover seeds. When found in these seeds YELLOW TREFOIL (Medicago lupulina, L.) C O P Y R I G HT 1 9 32 B Y O . M, S C O TT & S O NS C O. it is very difficult to remove as well as to recognize. We recall having once seen an almost perfect stand of Trefoil in an athletic field which had shortly before been sowed with a grass mixture. There was no accounting for the weed because Trefoil seed is not found in the grasses. Later it was discovered that several inches of topsoil had been brought in from bottom ground along a river. This soil was fairly alive with the seeds of Trefoil. They needed only cultivation to arouse them to activity. Accounting for Present Prevalence One of the best known seed analysts in the country volunteers this comment: "I think likely soil conditions may have had something to do with its de- velopment. Undoubtedly the lack of moisture affects Trefoil and makes it more noticeable, because other grasses die out and this plant, having a deeper rootstalk, subsists. We have had an in- sufficient amount of rainfall the past five years. The plant may therefore have had an advantage over less deeply rooted plants and has obtained a good foothold. We have noticed the increase in the growth of this weed in lawns of this area" [New Jersey]. Methods of Control A large area badly infested with Tre- foil should be rebuilt or, if there is no objection to White Clover, a heavy seed- ing of it will usually crowd the Trefoil out. When once discouraged by the crowding method, other grasses may be introduced since clover is not liked by many good lawn enthusiasts. Small patches of Trefoil may be removed by hand when the ground is wet. This should not be delayed until after the plants have gone to seed. Cornell Uni- versity, in one of its bulletins, advocates killing Trefoil by spraying with an iron sulphate solution, the same as for Dan- delions. Dissolve 4 pounds of this chemical in 5 to 10 gallons of water and apply this solution to 1000 square feet of turf infested with Yellow Trefoil. For the use of iron sulphate see Lawn Care Number 6 for August 1929. information further about Because Trefoil is not unsightly it is sometimes disregarded in a lawn until it becomes so widespread that its eradi- cation is a serious problem. We advise being on the lookout for this weed and suppressing it before it becomes too ambitious. D ig Plantain Now We are indebted to Mr. G. A. Helgert, of Milwaukee, for this timely thought: "During the month of August [and we imagine September, too] Plantain is very loosely anchored and can be easily pulled out by hand." However, the seed heads should be cut off during the summer to prevent new plants starting. 0 Fall Planting Best "My man-of-all-work evidently seized the psychological moment for planting the seed received from you the last of August. Within five days after plan- ting there was a beautiful green velvet with an inch pile where bare ground had been. Now it is several inches long and brilliant green in color. I am hop- ing I have converted the man to fall planting."—Dr. Hope Sherman, 2915 Coleridge Road, Cleveland Heights, Ohio. O. M. S C O TT & S O NS CO. M A R Y S V I L LE • • O H IO EVERY PACKAGE OF SCOTTS L A WN SEED ARS THIS TRADE-MARK A ND IS SEALED FOR YOUR PROTECTION 2 21 a