Cogongrass
Also known as: Imperata cylindrica
Noxious weed — illegal to plant in many states
When & where
Germination
Spacing & depth
How to plant
Firm the seedbed, broadcast evenly, rake in shallowly and keep the surface damp until the seedlings are established. Cut back ornamental grasses to a few inches in late winter, before new growth starts.
Grower's tip
Listed noxious weed — do not plant it. This page is for identification and removal only. Imperata cylindrica — Cogongrass.
Soil preferences
Almost any free-draining soil; most ornamental and prairie grasses prefer it lean.
5.5–7.5
None needed. Rich soil makes clumps flop.
Watering
Water through establishment, then only in extended drought.
Soak the root zone; overhead is fine on grasses.
Overwatered: floppy, splayed clumps. Underwatered: browning tips, early dormancy.
Prefers top-watering — Top-water (overhead sprinkler or rain) is the norm — grains are wind-pollinated and tolerate wet foliage well. Rice grows in standing water. Bottom-watering isn't practical for broadcast grain patches.
Temperature tolerance
Broad — warm-season grasses want 75–95°F, cool-season 60–75°F
Down to the species' rated zone minimum
Most perennial grasses go dormant with frost and return from the crown.
Container growing
Possible with the right cultivar
5–15 gal (19–57 L) for ornamental clumps
Clumping types behave in pots; running types will escape any bed you give them.
Detailed harvesting
Cut ornamental clumps back to 4–6 in (10–15 cm) in late winter, before new shoots emerge. Leave the winter structure standing until then.
Post-harvest storage & preservation
Dry seed heads upside down in a paper bag for arrangements or re-sowing.
Culinary, medicinal & other uses
Movement and winter structure, erosion control, meadow and prairie planting, wildlife cover.
Medicinal or traditional uses are shared for interest only — this is not medical advice. Consult a qualified professional before using any plant medicinally.
Seed saving
Wind-pollinated — expect crossing between nearby species.
Not practical outdoors.
Strip ripe seed heads into a bag once they shatter easily, then dry and clean.
Your zone's planting calendar
Pick your USDA hardiness zone and we'll estimate the key dates for cogongrass in your area. These are regional averages — always check your own last-frost forecast before sowing.
My Cogongrass notes
Cogongrass seeds on hand
Track packets and loose seeds you already have. Private to your account.
Par level — leave at 0 for no alert. Anything below par shows on Seed Starting and your shopping list.
Order more seeds
Running low? Reorder from one of these seed stores.
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