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 Ninth Year Number 39 POA ANNUA discussing THE chief difficulty in this child of N a t u re is to k n ow whether to call it a weed or a desirable grass. As its name indicates, Poa A n n ua is an A n n u al Bluegrass which matures seed inside of a year and then dies. It owes its con- tinued existence the fact that it is a prolific seeder even when kept closely cut. to Even then there was consider- able difference of opinion as to its value. that are Poa Annua is one of the few grasses found throughout the U n i t ed States. It even grows in tropical America in high altitudes. In the warmer sections it thrives during the winter months, but dies in summer. Some of our southern golf courses have l u x u r i a nt winter fairways composed almost entirely of Poa Annua, while in the latitude of Minneapolis it makes up a good percentage of golf course the summer months. turf during the received The name and fame of Poa Annua appear in some publications on turf grasses but it is also listed in rogue's gallery. Each year scores of sam- ples are from folks who have chanced upon a patch of it in their lawns and classified it in their minds as a weed. Others send us these specimens and report a beautiful and luxuriant growth in shaded areas where nothing would ever grow before. We are therefore busily engaged in telling one group how to eradicate Poa Annua while another is being instructed how to encourage it. It is probable that Poa Annua was brought into this country from Europe in early Colonial times. Printed descrip- tions of in English publi- cations dating as far back as 1825. it appear among An Abundant Seeder Like the ever welcome Crocus, b r i g ht green POA ANNUA patches of Poa Annua first harbingers of the are spring. This grass in flower before other varieties have even become green. Seed production starts in early spring and continues until hot weather when many of the old plants die. New plants spring up in early fall to continue the seeding cycle until cold weather. frequently is This seeding habit is the principal identifying characteristic of Poa Annua. Not only are seeds produced during the C O P Y R I G HT BY O. M. S C O TT & S O NS C O. greater part of the year but they develop even when the grass is cut at less than half an inch as it is on golf course put- ting greens. Poa Annua seed is produced com- Its avail- mercially only ability is irregular depending on har- vests and the hazards of ocean traffic. in Europe. Growth Not Vigorous distinguishable in color, making The leaves of Poa Annua are bright them yellow-green readily from other grasses which have more of a bluish cast. As approach maturity the grass becomes paler in appearance. This is due in part to the straw colored seed heads. seed heads the Generally speaking, the plants of Poa Annua are not vigorous. The blades are soft and the roots are shallow. There is a slight creeping tendency but the rapid spread of Poa Annua in certain places is due to its seeding habits rather than its ability to send up new shoots at the stem joints. The seeds from a single plant may be responsible for a patch a foot square in a few months' time. indicate is such a hearty it spring Since it would that Poa grower Annua likes a cool moist condition. This is true. It may be admired for its rich green color and thick sod but it must be mistrusted for its fickleness. As hot weather arrives and good grass is most needed and appreciated, Poa Annua to disappear. Sometimes the first hot blasts of sum- mer will turn it brown or cause a quick and complete fade-out. is very likely Adapted to Shade One place where it is apt to survive is in moist, shaded places. In fact, Poa Annua is usually at its best in the shade. Many are attracted to it because of that feature. But even in shade it may go away quickly because of its suscepti- bility to fungus diseases. What to Do About It it to hold Those who like Poa Annua have in tried special maintenance methods an attempt through hot weather. It is difficult to maintain since the plants never have much reserve strength because of abundant seed pro- duction. These efforts have been con- fined mainly to golf course putting greens where Poa Annua is sometimes preferred to other grasses. Frequent topdressing with compost combined with moderate applications of fertilizer will help to keep it. Although moisture loving, Poa Annua does better in fairly well drained soils. This is because it affords the shallow roots a plentiful supply of oxygen. If Poa Annua is not wanted it is hard to control when growing under favor- able conditions. About the only sure way is to prevent seed production by removing the individual plants in early spring before they start seeding. Even then control will not be complete because of the sprouting of dormant seeds which may have carried over from previous seasons. Some authorities recommend seeding Creeping Bent into areas infested with Poa Annua. While the Bent may not crowd out the Poa Annua it will per- sist during the summer months and provide a good turf in the absence of this temperamental annual variety. Poa Annua can be destroyed by chemicals but other grasses in the area will suffer the same fate. Small patches can be smothered with any material that keeps out light and air. O. M. SCOTT & S O NS CO. MAR Y S V I L LE • • O H IO EVERY PACKAGE OF SCOTTS L A WN SEED :D BEAR MARK AND IS SEALED FOR YOUR PROTECTION 2 39 a