Indian Steel, Sorghastrum

Indian Steel Ornamental Grass Seed

Steel-blue blades create refined upright prairie texture
Clumping plants typically reach about five feet
Golden fall color remains attractive through winter
Favorable conditions may produce seven-foot growth

See product details

Key Attributes

Botanical Name

Sorghastrum nutans

Days to maturity

135 Days

Sun

Full Sun

Packet

25 Seeds

Zones 4–9 Check your growing zone

About Indian Steel, Ornamental Grass Seed, Ornamental Grass Seed

Indian Steel is a clump-forming perennial grass with an upright, open habit typically growing upwards of 5' tall. Under the right circumstances it can be 7-8' tall. Features slender (1/2" wide), blue-green leaf blades (8-12" long) which turn yellow in fall and retain some gold color throughout the winter.

Growing details

Planting

Sow Depth

1/16"

Days to Germination

10–30 days

Germination Type

A - No Pretreatment

In-row plant spacing

18-36"

Plant profile

Life Cycle

Perennial

Hardiness Zone

Zones 4-9

Plant Height

84 inches

Growth Habits

Clumping, Upright

Seed & variety

Seeds Per Ounce

15,153

Color

Blue

Seed Type

Open Pollinated

Before Planting

Match the planting site to the ornamental grass species, favoring full sun and well-drained soil for most types. Remove perennial weeds thoroughly before sowing because they are difficult to separate later. Prepare a firm seedbed and use fresh seed without routine pretreatment unless the species requires otherwise.

Planting

Direct sow ornamental grass after the recommended seasonal or temperature requirement is met, or start seed indoors 6–8 weeks earlier for more controlled establishment. Keep the medium consistently moist until emergence and provide strong light afterward. Harden transplants gradually. Thin seedlings only where individual specimen plants are intended; mass plantings should follow the separate seeding-rate guidance.

Watering

Water ornamental grass regularly until established, then irrigate deeply only when the soil becomes dry. Avoid frequent shallow watering and saturated conditions, which encourage weak growth or root disease.

Fertilizer

Top-dress ornamental grass with compost or apply one balanced feeding in spring. Additional fertilizer is rarely needed unless growth is weak or a soil test identifies a deficiency.

Harvesting

Cut ornamental grass flowers when blooms are well colored and at the opening stage best suited to display. Harvest during the cool morning with clean shears, leaving healthy foliage for continued flowering.

Tips

Divide crowded ornamental grass clumps every few years to restore vigor. Deadhead for repeat bloom, or leave selected seed heads standing through winter to feed birds and provide structure.

Pests & Diseases

Rust, leaf spots, smuts, and crown rots vary among ornamental grass species. Identify the grass before diagnosing. Remove infected blades after dormancy, divide congested clumps, and avoid wetting foliage late in the day. Discard divisions with blackened crowns or abnormal seed heads rather than spreading them.

Watch ornamental grass buds and foliage for aphids, thrips, spider mites, Japanese beetles, slugs, and caterpillars. Look closely beneath leaves and inside buds, where early infestations are easiest to control without broad-spectrum products.