Purple Fountain Grass - Growing & Care

Pennisetum setaceum 'Rubrum'. Photo by: Proven Winners.

Botanical name:

Pennisetum setaceum 'Rubrum'

Common name:

Purple fountain grass

Zones:

9 to 11, grown as an annual in colder climates

Height/Spread:

3 to 5 feet tall and 2 to 4 feet wide

Exposure:

Full sun to partial shade

Soil:

Average, well-drained

Water:

Medium, consistent water throughout growing season

Color:

Burgundy-red leaves, burgundy-purple flowers in bottlebrush-like spikes

Bloom time:

July to October

Diseases and Pests:

No serious insect or disease problems.

When to Plant:

If you are planting in the fall, do so at least a month before the average first frost.

Water:

While they will tolerate dry conditions and are quite drought resistant, purple fountain grasses will look their best with regular watering.

Pruning:

In areas where purple fountain grass is being grown as a perennial, it should be cut back to just a few inches above the ground in late winter or early spring before new growth begins to ensure a full and healthy plant. Cutting back will also decrease the fire danger as fountain grass turns brown and dry in winter and becomes extremely flammable.

Photo by: Müller / McPhoto / Alamy Stock Photo.

Purple fountain grass makes a dramatic statement no matter where it is used:

• Foundation plant for a larger grouping
• Alone as a specimen
• Accent in perennial beds and borders
• Alone or as a centerpiece for a container
• In a desert or rock garden
• Ground cover
• Median strips, parking lot borders, and erosion control

Some varieties of pennisetums will readily self-seed and become invasive in the warmer areas where they are grown as perennials. However, according to Missouri Botanical Garden, “‘Rubrum’, sometimes commonly called purple or red fountain grass, is a burgundy-red leaved cultivar that is not invasive under any circumstances because, unlike the species, it rarely sets seed.” However, be careful if you grow several cultivars together because with cross-pollination, you might get viable seed.

Other colorful non-invasive ornamental grasses:

'Fireworks’ (variegated red fountain grass) has bright, red and green variegated leaves with purple tassels and is slightly smaller than ‘Rubrum’. 'Sky Rocket' has green and white striped foliage with white plumes, and is also slightly smaller than 'Rubrum'.