by Dr. Robert Black, Consumer Horticultural Specialist
When large, white, silken plumes begin emerging from pampas grass, you can be sure that the fall season is not far away. Pampas grass, like chrysanthemums and poinsettias, flowers when days get shorter. These plumes are flower stalks which rise to a height of twelve feet and differ in appearance between male and female plants. The female plants produce plumes that are broad and full due to silky hairs covering the tiny flowers which make up the plume.
The male plumes appear narrow and thin because of the absence of hair on the flowers. However, the difference in appearance is not so obvious that many people observe any difference between male and female plants. There is also considerable variation among plants in growth habit, period of flowering, and size and shape of plumes. Therefore, if uniformity and large plumes are desired, purchase plants when they are blooming in late August or early September.
Pampas grass can be a very attractive and functional plant when used correctly in the landscape. It can be used as a specimen plant in isolated locations on large lawns. It is probably best used as a screening plant for sunny locations. Unfortunately, pampas grass is often used as a foundation plant. It is usually purchased from a nursery as a small plant and planted very near the home. The plant will look great the first year, but after several years it usually grows so large that it will be difficult to find the house for the pampas grass.
In selecting sites for pampas grass, regard should be paid to the danger of injury to passers-by from contact with the very sharp saw-like edges of the leaves. Also, pampas grass should be planted where it will receive full sun most of the day. It will grow very slowly and usually will not produce plumes when grown in shady areas. Pampas grass is used frequently in landscapes along the coastline because of its tolerance to salt.
Once established, pampas grass is practically trouble-free. There is no need to spray for insects or any other bothersome garden pest. It will grow in most soils and responds favorably to frequent fertilization. To obtain good growth and plume production , pampas grass should be fertilized with a complete fertilizer at the rate of two pounds per 100 square feet four times each year.
In north Florida the leaves are often killed by freezing temperatures in the winter, but this does not impair the screening value of pampas grass and new leaves will arise from the rhizomes in the spring. Before growth begins in the spring, prune away brown leaves and dead materials that accumulates at the base of plants. It is advisable to move slowly and wear jeans, a long sleeve shirt, gloves and protective eye glasses when pruning pampas grass. The sharp leaf blades will cut through the skin of hands, arms, legs and other unprotected parts of the body.
The plumes of pampas grass are highly prized for indoor decorations. Plumes used for this purpose should be cut as soon as they have fully emerged. They can be used in dried arrangements immediately after harvesting or dried by hanging upside down and used later. If mature plumes are brought indoors, they will fill the home with delicate fluffy flowers which can be a bigger problem than a shedding dog or cat. This shedding can be prevented by spraying mature plumes with hair spray.