Pampas grass, Latin name Cortaderia selloana, is an easy to care for and durable ornamental grass that forms large clumps up to 10 feet wide and high. Attractive white plumes that look similar to cotton candy appear on large flower stalks in summer and fall. Pampas grass is popular for home landscapes, but it must be planted in an area with plenty of room to grow. Minimal care is required for pampas grass to thrive in most areas of the country.
Plant pampas grass in mid-spring in a location that receives full sun to light shade and has well-drained, loamy soil. Dig a hole about three times as wide as the root system and of equal depth. Spread the roots with your hands, place the plant into the hole and back-fill with soil. Space plants 6 to 8 feet apart for mass plantings.
Water pampas grass thoroughly after planting to compact the soil and encourage growth. Continue providing water once every two weeks for the first year. Water only during periods of drought once plants become established, usually after about two weeks with no natural rainfall. No additional supplemental watering is required for mature plants.
Feed pampas grass using a 10-10-10 NPK fertilizer three times per year in March, May and September during the first year of growth. Reduce feeding to once per year in March beginning in the second year of growth. Refer to the instructions on the packaging for proper dosage. Water thoroughly before and after applying fertilizer.
Prune pampas grass in early spring around February. Wear leather gloves to protect your hands from the sharp blades of grass. Tie a piece of rope around the entire plant about 4 feet from the ground and use a power weed trimmer to remove all the foliage and flower stalks above 12 inches in height.
Divide pampas grass clumps in spring, shortly after pruning for the best results. Dig up the plant and use a shovel to divide the roots into several new plants. One clump can typically be divided into 6 or 8 new pampas grass plants. Replant the divided clumps immediately and begin caring for them as usual.