- Exposure: Full sun
- USDA Hardiness Zones: 3 to 9
- When to plant: Early spring to early fall
- Pests and diseases to watch out for: Aphids, rust
How to Plant Ornamental Grasses
Dig a hole about twice the width of the pot. Set the plant in the hole so that the base of the plant is at ground level. Gently loosen and spread out any roots that are wound around the plant. Feed with compost, backfill the soil, water, and mulch to retain moisture and keep weeds down.
- Cool season (these perennial types start growing in early spring when temperatures are cool, going dormant in summer): Blue Fescue, Blue Oat Grass, Foerster's Feather Reed Grass
- Warm season (these perennial types grow best during summer and thrive until a hard freeze): Little Bluestem, Switch Grass, Japanese Windgrass
- Annuals/tender perennials (these must be planted every year, although some survive the winter in warmer climates): Purple Fountain Grass, Purple Millet, Vertigo Fountain Grass
How to Care for Ornamental Grasses
Grasses typically are pretty tough, but keep new plants watered the first few years in order to establish healthy roots. As with most perennials, they usually don't appear to be growing much the first year but tend to reach their full height by the third season in the ground. Once established, they're fairly drought-tolerant.
Do ornamental grasses need to be cut back?
Absolutely. If you don't, they tend to get ratty-looking. Trim cool season grasses in early spring, raking out dead leaves or cutting back the entire plant to about two inches above the crown, or base of the plant. Cut back warm season grasses in late winter or early spring if you prefer to leave the seed heads in place to provide winter interest in the garden.
When should you divide ornamental grasses?
If your grass has gotten too big for its location, if the center of the clump looks dead, or if the plant is floppy and sprawling all over the place, it's probably time to divide your plants. Instead of trying to dig up the whole thing, use a spade to dig around the outside of the plant, chunking off small sections on the outer edges. Replant the pieces elsewhere. It's best to do this before the plant's active growth cycle starts, so that's in early spring for cool season grasses and in late spring for warm season grasses.
Can you grow ornamental grasses from seeds?
Yes, it's less expensive than buying plants. But it will take several years to establish a plant that offers much visual impact in your garden.
GROWER TIP: "You don't want to fertilize ornamental grasses because that leads to lush growth, which tends to flop over," says Nancy J. Ondra, author of and . "And wear gloves and long sleeves when tending these plants, as many have sharp edges."