Pennisetum setaceum 'Rubrum'

Annual Purple Fountaingrass

Pennisetum setaceum ‘Rubrum’
Purple Fountain Grass / Red Fountain Grass

‘Rubrum’ is a warm-season ornamental grass grown for arching burgundy-purple foliage and soft, reddish-purple bottlebrush plumes. In warm climates it can behave as a tender perennial, but in cold-winter regions it is usually grown as an annual. The foliage forms a graceful fountain-shaped mound, with plumes appearing from midsummer into fall and aging to tan. It is especially popular in containers and seasonal color beds because it gives strong dark foliage contrast and movement.

Type: Tender perennial ornamental grass; usually grown as an annual in colder zones
Mature Size: 2–4 ft. wide × 3–5 ft. tall with plumes
USDA Zones: 9a–11b as a perennial; often treated as an annual in zones 8 and colder
Form: Arching, fountain-shaped clump
Light: Full sun; best color and strongest growth in full sun
Soil / Water: Well-drained soil; average water, drought tolerant once established; avoid wet winter soil
Bloom Time / Length: Midsummer through fall; reddish-purple plumes can remain attractive until frost
Wildlife: Seed heads may attract birds, though ‘Rubrum’ rarely sets viable seed; dense foliage provides temporary seasonal cover

Features & Landscape Uses:
Excellent for containers, annual beds, mixed borders, mass plantings, entry plantings, poolside planters, and tropical-style displays. The dark foliage pairs well with chartreuse sweet potato vine, coleus, lantana, canna, salvia, petunia, verbena, calibrachoa, sedum, and silver foliage plants. It is especially useful as a vertical accent in summer and fall containers.

Care:
Plant after danger of frost has passed. Water regularly during establishment, then allow the soil to dry slightly between waterings. Fertilize lightly; too much fertilizer can make growth floppy. In warm climates where it survives winter, cut old foliage back in late winter or early spring before new growth begins. In cold climates, replace yearly or overwinter container plants indoors in a bright, frost-free location.

Invasive Note:
The straight species Pennisetum setaceum can be invasive in some warm-climate regions. ‘Rubrum’ is generally considered much less invasive because it rarely sets seed, but local restrictions and invasive-plant guidance should be checked in warm regions before planting. 

Plant type

Ornamental Grass

Height

3-5'

Width

2-4'

Hardiness zones

9–11

Sunlight

Full Sun

Growth rate

Fast

Bloom time

Early Fall, Fall, Late Summer, Summer

Flower color

Brown, White

Leaf color

Purple

Fall color

Purple

Attracts

Birds

Soil

Average, Well Drained

Landscape use

Accent Plant, Container, Mass Planting

Shape

Arching, Clump, Fountain Shaped

Fruit

Yes

Deer resistant

Yes

Drought tolerant

No