Learn How to Grow Fountain Grass (Pennisetum)

Pennisetum spp.

Not ready to commit to hardscaping by adding a fountain to your garden? If so, fountain grass might be the perfect compromise.

A mounding ornamental, Pennisetum is a garden favorite that offers all the beauty of a fountain without the water.

It has cascading leaves and bottle brush flower spikes that look much like water bursting out of a fountain, if I do say so myself.

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Perennial in many places, fountain grass is an attractive option that produces dense, clumping growth.

It offers all-season interest with its lovely blades and small flowers on striking plumes. With many different types to choose from, this plant is adaptable and easy to grow.

Ready to learn more? Keep reading to learn all the tips you need to grow fountain grass in your landscape.

Pennisetum includes roughly 130 species, including two commercial crops – elephant grass (P. purpureum), which is used for biofuel and forage, and pearl millet (P. glaucum), which is edible.

Of course, this genus is best known for its gorgeous landscape ornamentals.

A few of the most popular for ornamental use are P. glaucum, P. setaceum, and  P. alopecuroides.

There are several that are perfect for landscaping, including P. glaucum, P. setaceum, and  P. alopecuroides as well as purple fountain grass (P. setaceum ‘Rubrum.’).

Though some botanists now classify these grasses under the genus Cenchrus, they remain widely known and sold as Pennisetum, the name used throughout this guide.

These plants are native to warm temperate and tropical areas of northern Africa, western Asia, Latin America, and Australia, and are prized for their appearance and hardiness.

The foliage remains attractive throughout the winter months, making this type perfect for all-season interest.

Fountain grass produces brush-like flower spikes that vary in color, depending on the type. They may be white, pink, purple, and other colors as well.

It is these spikes that serve as the plant’s namesake. They spring from the clump of foliage and look just like water spraying out of a fountain, really!

The spikes turn brown as seeds form and these also hang on until the late fall or early winter, when they shatter and spread.

Fountain grass seed was first introduced in the United States as early as 1883.

In most parts of the world, it grows easily and peacefully among other plants, and some varieties have naturalized in parts of Europe and North America.

How to Grow

Plant your fountain grass in a full sun location. While the plant can tolerate part shade, it won’t flower quite as well.

It grows best in warm climates with temperatures ranging from 75 to 85°F, though many cultivars can tolerate much cooler conditions.

This grass can be grown in most kinds of soil, but does best in fertile loam. Well-draining soil with a slightly acidic to neutral pH of 6.0 to 7.0 is preferred.

Test your soil prior to planting to get an idea of its nutrient content and pH level.

Water generously for the first three months after planting, providing about one to two inches of water per week if it is not supplied via rainfall alone.

You can measure your local precipitation levels using a rain gauge.

Once your plant has become established, watering can become less frequent, as fountain grass is quite drought tolerant.

Cultivars to Select

The following are some of the most popular cultivars of fountain grass to consider, and all of the options that I’ve included in this list are perennial varieties of P. alopecuroides.

There are also annual plants in the Pennisetum genus that you can grow, including P. setaceum ‘Rubrum,’ and other species as well.

Hameln

This cultivar is short and compact, growing to just one to three feet tall and wide. It grows best in Zones 4 to 11.

‘Hameln’

With its lovely soft, fluffy plumes and purple flowers, it makes a striking border. It has been awarded the Royal Horticultural Society’s Award of Garden Merit.

You can find ‘Hameln’ plants available from Nature Hills Nursery.

Jambalaya

A sterile cultivar from the University of Georgia’s breeding program, Jambalaya™ (P. alopecuroides ‘Tift PA19’) forms a tidy, upright mound of slender, arching green blades that turn golden-bronze in fall.

Hardy in Zones 5 to 9, it produces large, smoky, silvery pink plumes flushed with purple, aging to silver and fading to tan as they hold into winter.

Jambalaya™

It reaches about three feet tall with a spread of three to four feet. Being sterile, it sets no viable seed and will not self-sow the way the straight species does.

Find plants in #2 containers available at Nature Hills.

Moudry

One of the most popular and striking cultivars to consider, ‘Moudry’ is often referred to as black fountain grass.

It produces gorgeous dark purple or black flower spikes that appear in late summer to early fall, about three to five weeks later in the season than those of other options.

It grows to about two to three feet tall and reseeds with ease. However, it does not usually grow true to seed. Plants are hardy in Zones 5 to 9.

Praline

A compact, sterile cultivar from the University of Georgia’s ornamental grass breeding program, Praline™ (P. alopecuroides ‘Tift H18’) forms a tidy mound of narrow, arching green blades that turn amber and copper in fall.

From midsummer into fall it sends up soft, fuzzy bottlebrush plumes in tan flushed with pink, fading to a wheat color that holds into winter.

Praline™

Among the smallest of the sterile fountain grasses, it reaches roughly two to three feet tall in bloom with a spread of just over three feet.

Because it sets no viable seed, it stays put and will not self-sow the way the straight species does. Hardy in Zones 5 to 9.

You can find Praline™ available in #2 containers at Nature Hills Nursery.

Purple Fountain Grass

Purple fountain grass (P. × advena ‘Rubrum,’ often sold as P. setaceum ‘Rubrum’) forms an upright, fountain-shaped clump of narrow, deep burgundy-red blades.

In summer it sends up arching, foxtail-like plumes in burgundy-purple to rose-red that nod above the foliage and fade to tan as they age.

It reaches roughly three to five feet tall with a spread of two to four feet. Unlike the invasive species, this cultivar is sterile and rarely sets seed.

Purple Fountain Grass

Hardy in Zones 9 to 11, it’s grown as an annual in most of the country, where it puts on a full season of color before dying back with the first frost.

You can find this cultivar in one- and three-gallon containers at Fast Growing Trees.

Check out our guide to growing purple fountain grass here.

Maintenance

You can divide your plants every three or so years if the clump is getting a bit too big. We discuss this in more detail in the Propagation section below.

Prune or cut back in late winter or early spring to remove any old, dead plant material and control the height of the specimen.

Wear gloves when you do this, as the blades of these plants can be sharp!

Fountain grass should die back naturally as part of the growing cycle, even in warmer climates where they are grown year-round.

The plants won’t start growing each year until the soil has warmed up, so you should have time at the end of winter to cut last year’s growth back before new shoots appear.

Trim the foliage back to about three to six inches above the ground with a pair of hedge trimmers.

Learn more about pruning ornamental grasses here.

To prevent self-seeding, purchase infertile cultivars, or remove seed heads before they open and spread their seed around the garden.

If you aren’t able to catch them all before they pop, plan to do a little weeding around the garden the following season to pull up unwanted volunteers.

Propagation

These plants can be grown from seed in some cases, or they may be propagated by division.

An easy way to get started is to transplant potted starts from the nursery.

From Seed

There are some cultivated Pennisetum that are sterile so these will not be able to be propagated from seed.

Growing sterile types is generally considered an advantage, since it helps to prevent unwanted spread.

Types with fertile seed tend to self-seed readily – something that can border on annoying for gardeners who haven’t planned for this effect!

These plants rarely become invasive in cold climates like they can in warmer areas, a definite advantage worth noting.

Hybrid cultivars won’t grow true to seed, meaning the plants that result may have unexpected qualities.

If you want to grow fountain grass from seed, you can sow indoors in early spring.

Fill three- to four-inch pots or 10-by-20-inch trays with a seed-starting mixture.

Sow one to two seeds per pot, or space them three to four inches apart in trays. Just barely cover the seeds with soil.

You can also choose to start seeds outdoors after the last expected frost date in your area, following the same recommendations for spacing as described above in pots or in the ground.

Be sure to keep the soil evenly moist but not waterlogged until germination.

Seedlings should appear within two to three weeks. Once seedlings are established, the soil surface can be allowed to dry out between waterings.

When the plants are just two weeks old, it’s safe to move them outside, provided there is no risk of frost in the forecast.

Transplant according to the instructions below.

By Division

These plants have a clumping habit and will spread via underground rhizomes.

If you choose to divide your mature fountain grass plants to propagate new ones, wait until late winter or early spring.

This will give your new plants enough time to become established before the summer heat.

The soil should be warm enough to work, and your plants should be dormant or just starting to put on fresh spring growth.

Begin by cutting back any existing top growth to about two to three inches above the soil line.

Dig up the entire root ball of the plant if you can, using a shovel to work around the edges.

In some cases, particularly if your plant is very old or very large, you may not be able to dig it up entirely, and will have to work in sections instead. Feel free to recruit a friend to help!

Once you have your divisions, replant the parent.

You can follow the steps described below to transplant divisions – set them at the same depth that they were growing in the ground previously.

Learn more about how to divide perennials in our guide.

Transplanting

To transplant, start by digging a hole twice as wide and the same depth as the container the plant is currently growing in.

Or in the case of divisions, as deep as the root ball.

If you have multiple plants, provide at least three feet of space between them for adequate airflow.

Remove them from the containers and gently loosen the roots.

Add a bit of compost to the planting hole, then water, and place the transplant in the hole. The crown should be positioned slightly below the soil line.

Fill in the rest of the hole with soil, firm it in place, then water deeply.

Pests and Disease

Ornamental grasses such as these are known for being robust, and they can ward off many common problems.

However, there are a few insects and diseases you will want to keep an eye out for.

Pests

Most insects and other animals (including deer!) leave fountain grass alone. Be on the lookout for aphids and mites.

Aphids

Aphids (Aphidoidea spp.) cause damage by puncturing the blades to suck out the sap with their tiny mouthparts.

These small, often green insects might look harmless, but they can cause the foliage to turn yellow and become weak.

You can get rid of aphids by pulling them off your plants by hand, aiming a sharp spray from the hose at them, or applying neem oil.

Natural predators such as ladybugs and green lacewings can also be effective.

Mites

Mites (Tetranychidae spp.) are similar to aphids in that they are small and difficult to detect.

These nearly microscopic arachnids also suck juices from grass blades, causing the plants to turn yellow.

You might not be able to see the mites with your naked eye, but a magnifying glass can help if you know what to look for.

Plants that become too dry are targets for mites, who favor low humidity and dusty conditions.

You can treat a heavy mite infestation in a similar way to how you would deal with aphids.

Hose down the foliage to knock the mites off, encourage beneficial predatory insects to take up residence, or spray with an insecticidal soap or pyrethrin product.

Learn more about spider mites here.

Disease

As with pests, your best line of defense in preventing most fountain grass diseases is to do whatever you can to keep your plants healthy.

These are some diseases you should keep an eye out for.

Rust

Rust (Pucciniales spp.) is a fungal disease that can target all kinds of ornamental plants, including fountain grasses.

It causes small yellow or red-orange blisters on grass blades.

These areas may enlarge and turn a darker brown in some cases, taking on the appearance of large, streaky blotches. The blades may even wilt and die back.

Overhead watering can foster overly moist conditions that will encourage the development of fungal diseases like this one.

Powdery Mildew

Like rust, powdery mildew is a fungal disease caused by Golovinomyces orontii that results in powdery-looking blotches to appear on leaves.

You may be able to treat powdery mildew by applying a fungicide at the first sign of a problem. It’s far easier to prevent, though, as this can be done by planting in full sun.

Although fountain grass can tolerate some shade, fungal problems are much more common in dark, humid conditions.

Again, watering at the soil level as well as providing proper spacing between plants to increase air circulation can also help to prevent this disease.

You can learn more about how to treat powdery mildew here.

Best Uses

Fountain grass is best grown as a specimen plant or focal point in small landscapes.

It can even be grown in containers, especially if you’re vigilant about pruning to control its growth.

It works well just about anywhere, including in rock gardens, borders, around water gardens, or even along the banks of ponds or streams provided there is sufficient drainage.

You can grow it in small groups with other shrubs and perennials to add contrast and texture during all stages of its growth.

It can even provide a soft, informal look as an edging plant!

Of course, you can always cut the flower spikes to be placed in a vase indoors.

And let’s not forget the winter interest offered, either dried and added to arrangements, or left on the plant until you prune it back in early spring.

No matter the season or location, fountain grass is sure to add a special something to your landscape.

Cultivate Constant Cascading Beauty

If you are looking for a stunning ornamental grass with interesting foliage and attractive flowers, fountain grass is the way to go.

There are many cultivars for you to choose from, so gardeners in plenty of growing zones should find what they’re looking for with these plants.

A consistently easy-care option, fountain grass makes a statement when grown by itself or with suitable companions.

Do you grow fountain grass? Which varieties are your favorites? Be sure to share your landscaping ideas for this elegant plant in the comments section below!

And if you found this guide helpful, be sure to check out more information on growing ornamental grasses next:

• Easy Landscaping with Ornamental Grasses: Simple Tips for Carefree Success
• Learn How to Grow Zebra Grass
• Learn How to Grow Black Mondo Grass