Pennisetum, commonly known as fountain grasses, are a popular ornamental grass grown for their graceful, fountain-like appearance. With their arching foliage and plume-like blooms, pennisetum add texture, movement, and interest to gardens and landscapes. Growing pennisetum is relatively easy, but there are some key things to know about caring for these ornamental grasses.

Selecting the Right Pennisetum Variety

There are over 80 species of pennisetum, along with numerous cultivars and varieties. When selecting pennisetum for your landscape, consider factors like:

Plant size – Pennisetum range from petite types under 2 feet tall to towering varieties reaching 6 feet or more. Select the right size plant for your space.

Bloom color – Pennisetum plumes come in white, pink, purple, black, tan, and more. Choose a bloom color that complements other plants.

Bloom time – Most pennisetum bloom in summer or fall, but there are early and late blooming varieties. Stagger bloom times for extended color.

Hardiness zone – Know your USDA hardiness zone and choose pennisetum suited for your zone. Some are cold hardy perennials, while others are tender tropicals.

Sun exposure – Most pennisetum need full sun, but some like ‘Hameln’ tolerate partial shade. Check sun requirements.

Popular pennisetum varieties include:

‘Fireworks’ – Purple plumes on 4-5 foot plants. Hardy in zones 8-11.
‘Rubrum’ – Pink/red plumes on 3-4 foot plants. Hardy in zones 9-11.
‘Little Bunny’ – Dwarf variety under 2 feet tall with tan blooms. Hardy in zones 5-9.
‘Moudry’ – Black-purple plumes on 3 foot plants. Hardy in zones 6-9.
‘Skyrocket’ – White plumes on 5+ foot tall stems. Hardy in zones 9-11.

Planting Pennisetum

When to Plant

Pennisetum can be planted in spring after the last frost date or in summer during the growing season. Container-grown grasses can be planted anytime. Just be sure to water transplants regularly until established.

Soil Needs

Pennisetum grow best in fertile, well-draining soil. Improve drainage in heavy clay soils by mixing in compost. In sandy soils, add compost or peat moss to increase moisture retention. Test soil pH and amend if needed – pennisetum prefer a neutral pH around 6.5-7.0.

Sun and Exposure

Select a planting site with full sun for most pennisetum varieties. Some tolerate partial shade, especially in hot climates, but may bloom less. Avoid shady sites.

Planting Process

When planting pennisetum:

Dig a hole 2-3 times as wide and just as deep as the root ball.
For potted plants, gently loosen the roots before planting.
Position the plant upright in the hole, making sure the crown (where stems meet roots) is level with the soil surface.
Backfill the hole with native soil, firming the soil around the roots.
Water thoroughly after planting.
Space plants 12-36 inches apart depending on mature size.

Caring for Pennisetum Grasses

Proper care is important for the health and performance of pennisetum. Key care guidelines:

Watering

Establish a deep watering routine 1-2 times per week.
Avoid frequent shallow watering which weakens roots.
Check soil moisture before watering – don’t water on a fixed schedule.
More water is needed in hot and dry conditions.
Pennisetum are drought tolerant once established but need sufficient water for best growth.

Fertilizing

Fertilize in spring as new growth appears.
Use a balanced fertilizer like 10-10-10 or a specialized grass fertilizer.
Follow product instructions for correct rate and timing.
Fertilize every 4-6 weeks during active growth.
Stop fertilizing after September to harden off for winter.

Pruning

Cut back previous years’ foliage in late winter or early spring.
Remove spent plumes regularly to encourage new blooms.
Thin or divide dense clumps every 2-3 years as needed.
Some pruned varieties regrow foliage for multi-season interest.

Pest and Disease Control

Pennisetum are not prone to serious pests, but watch for caterpillars, mites, and scale insects.
Diseases are rare, but rust, leaf spots, or powdery mildew can occur.
Remove and destroy infected foliage. Avoid overhead watering.
Apply neem oil or appropriate fungicides as needed.

Overwintering

Perennial types need winter protection in zones 5-8. Cut back in fall and mulch roots.
Tropical varieties must be overwintered indoors in colder climates.
Some species self-seed readily – remove young seedlings to control spread.

Common Problems and Troubleshooting

Issue	Cause	Solution
No blooms	Too much shade, improper pruning, overfertilization	Move to full sun, only prune in spring, reduce fertilizer
Sparse foliage	Insufficient water, overly dense clumps	Increase water, divide plants
Foliage yellowing	Poor drainage, nutrient deficiency	Improve drainage, fertilize plants
Leggy growth	Inadequate sunlight	Relocate to full sun location
Plant decline	Excess moisture, cold damage, root rot	Improve drainage, use winter protection, treat disease
Self seeding	Allowing plumes to go to seed	Remove spent plumes before seed heads form

Uses in Landscaping and Design

With their graceful form and colorful blooms, pennisetum add visual interest to gardens and landscapes:

Specimen planting – Showcase as a focal point or thriller plant. Provides height, color, and texture.
Mass planting – Group multiples together as a pennisetum lawn or living screen. Creates a sense of movement.
Borders and beds – Excellent spiller or edging plant along walks, fences, and borders. Softens hard edges.
Containers – Compact dwarf varieties work well in patio pots and planters. Adds height and fullness.
Poolside or seaside gardens – Tolerant of wind, salt spray, and sandy soils. Adds fine texture.
Cut flowers – Harvest plumes for fresh cut flower arrangements. Dried plumes also used.
Erosion control – Extensive root systems prevent erosion on slopes and bare areas when massed.

With their ornamental appeal and versatility in the landscape, it’s easy to see why pennisetum are so popular! Follow proper care and site selection, and these fountain grasses will provide enjoyment for years to come.

Frequently Asked Questions About Growing Pennisetum

What are the different types of fountain grass?

Some common pennisetum varieties include ‘Fireworks’, ‘Rubrum’, ‘Little Bunny’, ‘Moudry’, ‘Skyrocket’, ‘Karley Rose’, ‘Red Riding Hood’, and ‘Princess’. There are also many hybrids and cultivars available.

Are fountain grasses annuals or perennials?

It depends on the variety. Some pennisetum like ‘Fireworks’ and ‘Rubrum’ are perennial in zones 8-11. Others like ‘Little Bunny’ are cold hardy perennials good for zones 5-9. Tropical varieties are grown as annuals in colder climates.

How big do fountain grasses get?

Pennisetum range from petite 12-inch types to varieties reaching 6 feet tall or more at maturity. Select the right size for your space. Dwarf cultivars work well in containers.

What are the best fountain grasses for pots?

Good pennisetum varieties for containers include ‘Little Bunny’, ‘Red Riding Hood’, ‘Fireworks’, ‘Moudry’, and ‘Princess’. Choose dwarf and compact types under 3 feet tall.

How do you care for pennisetum grasses?

Pennisetum need full sun, moderately fertile soil, regular watering, and good drainage. Fertilize in spring and summer. Cut back previous years’ foliage in late winter before new growth begins. Divide congested clumps every 2-3 years.

How fast do fountain grasses grow?

Growth rate depends on the variety, but most fountain grasses grow fairly quickly. They can reach full size within 1-2 growing seasons. Proper care like fertilization and adequate moisture accelerates growth.

Do fountain grasses spread?

Some varieties like ‘Fireworks’ readily self-seed and spread. Containment or removal of spent plumes helps control unwanted spread. Clump-forming types expand slowly outward but are not aggressive spreaders.

Are pennisetum grasses deer resistant?

Generally, yes. The stiff foliage and texture of most pennisetum makes them unappealing to deer and other browsing animals. There are exceptions though, so check deer resistance for specific varieties.

When should I cut back fountain grass?

Cut back foliage to around 6 inches anytime between late fall and early spring. Many gardeners trim pennisetum in late winter just before new growth emerges. Removing old foliage promotes lush new growth.

Conclusion

With their graceful plumes and appealing textures, fountain grasses make a stunning addition to gardens. When provided with full sun, fertile soil, ample moisture, and proper care, pennisetum are easy to grow and rewarding plants. Their fine form, vibrant colors, and movement add beauty, height, and visual interest where ever they are planted. Choose varieties suited to your climate and space, follow the recommended care guidelines, and enjoy the wonderful ornamental effects of pennisetum.

How to Grow Pennisetum (Fountain Grasses)

This detailed guide covers everything you need to successfully grow pennisetum ornamental grasses. With their graceful, fountain-like form and showy plumes, pennisetum make excellent specimens in gardens and landscapes. Here’s how to select, plant, care for, and enjoy these beautiful ornamental grasses.

Overview of Pennisetum

Popular ornamental grass grown for fountain-like shape and plume blooms
80+ species available including many hybrids and cultivars
Hardy or tropical varieties ranging from 1-6 feet tall
Most have arching foliage and feathery, plume-like blooms
Provide movement, texture, height, and long-lasting color
Low maintenance once established
Useful for borders, beds, pots, erosion control, and as cut flowers

Choosing Pennisetum Varieties

Consider mature size for spatial needs
Select bloom colors to complement other plants
Factor in climate hardiness zone restrictions
Choose sun exposure needs (most need full sun)
Time blooms for extended color (summer vs fall bloom)
Popular hybrids: ‘Fireworks’, ‘Rubrum’, ‘Moudry’, ‘Little Bunny’

Planting Pennisetum

When

Spring after last frost
Summer
Anytime for container plants

Site

Full sun (some tolerate partial shade)
Well-draining soil enriched with compost
Neutral pH around 6.5-7.0

Process

Dig hole 2-3 times width of root ball
Gently loosen potted roots
Plant at same depth as in pot
Backfill hole, firm soil, water thoroughly
Space plants 12-36 inches apart

Caring for Pennisetum

Watering

1-2 times per week, avoid shallow watering
Check soil moisture before watering
More water needed in heat and drought

Fertilizing

In spring as growth resumes
Balanced fertilizer like 10-10-10
Every 4-6 weeks during growing season

Pruning

Cut back old foliage in late winter/early spring
Remove spent plumes to encourage new blooms
Thin or divide dense clumps every 2-3 years

Pest/Disease Control

Not prone to serious issues
Treat caterpillars, mites, scale as needed
Improve air circulation to prevent fungal disease

Overwintering

Use winter mulch in zones 5-8
Move tropical varieties indoors

Design Uses

Specimen/focal point plant
Mass planting for movement
Borders and beds to soften edges
Containers and planters
Poolside or seaside gardens
Cut flowers (fresh or dried)
Erosion control on slopes

Conclusion

With proper selection, planting, and care, pennisetum are easy to grow and provide long-lasting beauty. Their graceful, fountain-like form and colorful blooms make them a top choice for adding texture, movement, and visual interest to gardens and landscapes.