These plants enjoy moist, well-draining soils and are often drought-tolerant once established. They are not often bothered by pests or diseases and are generally rabbit and deer resistant. Besides yearly pruning and occasional watering, these grasses do not demand much attention.
Light
These plants thrive in full sunshine. They prefer at least six to eight hours of sunlight a day. A bit of shade is acceptable, but too much shade can cause these grasses to take on a leggy, floppy appearance and they might not flower.
Soil
The Pennisetum genus generally prefers rich, evenly moist soil that is slightly acidic. However, if the soil is well-draining and moist, these grasses can be grown in a mix of clay and sand as well.
Water
Regular watering will keep any variety of Pennisetum grass happy. The species within this genus prefer moist conditions, so water when the top of the soil begins to feel dry. Aim to keep the soil consistently moist, but never soggy. Some varieties are drought tolerant and will not need as much watering.
Temperature and Humidity
Pennisetum grasses enjoy warm, humid environments and can be grown as perennials in USDA Hardiness Zones 3 to 10. They thrive in sunny, hot, humid regions. However, these grasses can be grown as annuals in colder zones.
Fertilizer
Fertilizer is not normally necessary for the healthy growth of the Pennisetum species, but giving these plants some well-balanced fertilizer in the spring won’t hurt. This will help encourage healthy, plentiful growth.
Types of Pennisetum
Pennisetum setaceum ‘Rubrum’: Known as purple fountain grass, this variety is famous for its deep purple foliage and soft purple and tan blooms. This is a tender perennial that grows in zones 9-11 but is often used as an annual. They grow to be 4 feet tall and wide. Pennisetum messiacum ‘Bunny Tails’: This variety was named after its small, pink, fluffy flowers that resemble a bunny’s tail. It is a small variety that only grows to about 2 to 3 feet high. Pennisetum orientale: This variety forms a compact bush of foliage and soft, dusty pink blooms. It reaches a mature height of 4 to 5 feet tall. Pennisetum alopecuroides: This variety is the parent of many other cultivars. It produces 1 to 4 feet tall pinkish-purple blooms that mature to a soft brown.
Pruning
For perennial varieties of Pennisetum, you can cut foliage to the ground in late fall after the grass is done blooming. This will keep the area clean throughout winter and encourage new, healthy growth in the coming growing season. Some gardeners prize the winter interest provided by their ornamental grasses and prefer to cut them down in early spring.
Propagating Pennisetum
Propagating these grasses can easily be done through division in the spring. Here’s how:
How to Grow Pennisetum From Seed
You can also start Pennisetum grasses from seed. To directly sow seeds outdoors, follow these steps: To start seeds indoors, follow these steps:
Potting and Repotting Pennisetum
Many varieties of Pennisetum grow well in containers and are perfect for adding texture and interest to patio areas and porches. Soggy soil from trapped water can cause root rot in containers, so it is important to choose a large pot with good drainage holes. Fill the pot with well-draining soil and keep the soil moist, but not soggy. Choose a pot that provides several inches of growing room on all sides. When the grass outgrows its container, gently tip the container onto its side and tap the pot to loosen the root system. Slowly work around the pot until the plant can be slid out. Plant the grass into a larger container and fill it in with rich, well-draining soil.
Overwintering
Some varieties of these grasses cannot survive cold winters in zones 5 and below and are often grown as annuals in those zones. If you’re located in one of the northernmost hardiness zones, add a layer of mulch before the winter begins to help insulate the roots. If kept in pots, it is best to move the pot indoors before cold temperatures arrive.
