Purple fountain grass is named for the arcing spikes of purplish flowers that gracefully spray out of its mass of long, slender, burgundy-colored leaves. It is not a very cold-hardy plant, but it is well worth growing in cold-winter regions even if you can enjoy it for only two seasons out of the year. While it may be more expensive than other plants grown as annuals, purple fountain grass will delight you with a showy, multi-faceted display. A clump-forming ornamental grass variety, it is a tropical plant that is both deer-resistant and non-invasive.
The beauty of purple fountain grass makes it popular as a focal point in a mixed planting, and it is often used in container gardens. But you can also mass several of the plants together, such as in a border planting. These can also stand alone as specimen plants. Some like to use them to jazz up a foundation bed for the summer. Grouped with plants of a coarser texture, they can create a striking contrast.
Because the autumn seed heads of this plant are so attractive, purple fountain grass, like maiden grass, is very useful in fall flower gardens. The feathery seed heads (or "plumes") can later be cut for dried flower arrangements.
Botanical Name:
Pennisetum setaceum 'Rubrum'
Common Name:
Purple fountain grass, red fountain grass
Plant Type:
Perennial ornamental grass (grown as an annual in cold climates)
Mature Size:
3 to 5 feet tall and 2 to 4 feet wide
Sun Exposure:
Full sun
Soil Type:
Any well-drained soil
Soil pH:
Acidic to neutral
Bloom Time:
July
Flower Color:
Burgundy red
Hardiness Zones:
9 to 10
Native Area:
Africa, southern Asia
How to Grow Purple Fountain Grass
Although it can be planted nearly anytime, spring is the most suitable time for planting purple fountain grass. These plants need a sunny location with well-draining soil. Since mature plants can reach about 5 feet tall and nearly as wide, they should be given plenty of room in the garden with at least 3 feet between plants. Dig a hole both deep and wide enough to accommodate the roots and then water your purple fountain grass thoroughly after planting.
Purple fountain grass may need some staking for support. Plant it in an area protected from strong winds.
Light
This grass will tolerate some light shade, but it prefers full sunlight. Look for an area in your garden where it will receive full sun, as it also prefers warmer conditions.
Soil
Purple fountain grasses can do well in many types of soil as long as it is well-draining. Loamy soil provides the best results.
Water
Purple fountain grass is considered a drought-tolerant ornamental grass. Water new plants once or twice a week until they are established. Give time for the soil to dry to the touch between each watering. In areas that receive rain occasionally, you will not need to water the grass once it has become established. If you are cursed with a soil that is somewhat waterlogged, try a sedge grass instead.
Temperature and Humidity
If your winter temperatures remain above 20 degrees Fahrenheit, then purple fountain grass can be grown as a perennial and cut back in early spring each year. New growth will initiate as the temperatures climb.
Those in colder zones will have to make do with enjoying its vivid color and striking, vase-shaped form in summer and fall, unless they do not mind going through the trouble of overwintering it indoors.
Fertilizer
Fountain grass is hardy and grows fairly well in poor soil, but fertilizer will boost its growth. The grass will need additional nutrients when flowering. During that time (generally, the summer), use a general-purpose, slow-release fertilizer.
Varieties of Purple Fountain Grass
Pennisetum setaceum 'Fireworks' is another cultivar of the purple fountain grass species plant. Its leaves are variegated with burgundy in the middle and hot pink at the edges. It grows 3 to 6 feet in height, with a spread of 1 to 3 feet. It is a perennial in zones 9 to 10.
P. alopecuroides 'Burgundy Bunny': A cultivar of a relatively cold-hardy species of fountain grass in the Pennisetum genus, this variety stands 16 inches tall with a spread of 16 inches. The foliage has hints of red in summer, but the color intensifies to a deep reddish-purple in fall; the flower heads are buff-colored. It is suitable for zones 5 to 9.
P. alopecuroides 'Little Bunny': Another cultivar of P. alopecuroides, 'Little Bunny' stands 12 inches tall with a slightly greater spread. This variety lacks the colorful foliage of burgundy bunny but also features buff-colored flowers. Like 'Burgundy Bunny', it grows as a perennial in zones 5 to 9.
Pruning
The standard way to prune purple fountain grass is to cut it back severely in late winter or early spring, before it begins its new growth. This eliminates dead foliage and improves air circulation and sun exposure to stimulate the growth of new leaves. You can also selectively trim dead foliage and perform some light shaping on the plant anytime of year.
To cut back the plant in spring, put on work gloves, gather the leaves of each plant, and bind them with a rope or bungee cord. Use pruners or a scythe to cut the leaves straight across, 4 to 6 inches up from the base of the plant. Comb though the trimmed leaves by hand to remove dead blades and debris.
Propagating Purple Fountain Grass
Purple fountain grass can be propagated through seed or division. The plants may readily self-seed in the garden, but root division is a faster and more reliable form of propagation.
Seeds: This grass produces flowering stems, which are full of feathery seeds. Collect seeds when they are dry, usually in fall. Take the whole stem and allow the flower stalk to dry in a cool, dry place. Surface sow in good potting soil with just a dusting of sand on top. Water until the container is evenly moist, and then place the pot in a plastic bag or cover it with a plastic dome. Once you have seedlings with two sets of true leaves, transplant them to larger pots. Harden them off in spring and install in prepared containers or beds.
Division: Dig up the plant when it is going dormant and cut it into two or more sections with healthy roots and leaves. Use very clean, sharp implements to make your cuts, and discard any rotten or dead plant matter and roots. Replant immediately and keep the soil moist as the division settles into its new home.
Growing in Containers
Since this plant cannot tolerate winter well, it is a good specimen for growing in containers. You will need to bring it indoors or into a greenhouse for the winter.
If you choose to overwinter the plant, you have two options: Treat it as a houseplant and put it in a relatively cool room with sun exposure; or store it in a cool (but not freezing) location, such as a cellar. Water sparingly, but do not let the soil in the container totally dry out. You can return it to the outdoors in the spring.
Landscaping Uses for Purple Fountain Grass
Purple fountain grass looks wonderful with contrasting yellow flowers. You can also achieve a striking composition by striving for a contrast in texture, growth habit, and plant height. The leaves of cannas contrast nicely with purple fountain grass. If you are growing your purple fountain grass in a pot, move the container in front of oakleaf hydrangea in the fall. The contrasting texture of the shrub will provide an effective backdrop for the purplish fall foliage of the grass. For the foreground, install a short plant with a growth habit that contrasts with the upright purple fountain grass—for example, annual lobelia or blue fescue.