Grow woolgrass in wet soil or a rain garden, in full sun. Woolgrass is Scirpus cyperinus, also sold as wool grass.
Keep it in wet soil or a rain garden, in full sun
| Factor | Recommended | Avoid |
|---|---|---|
| Light | Full sun; light shade is fine in a hot summer | Do not site it in a dry, dark corner |
| Water | Wet soil, a rain garden, or a few inches of shallow water | Do not let the ground dry, even once |
| Soil | Mud, sand, gravel, peat, or muck that stays wet | Do not plant it in a mix that drains in a day |
| Spread | Let short rhizomes fill a wet shelf you can contain | Do not toss extras into a wild marsh or storm drain |
woolgrass wants wet ground in full sun. Heat is fine if the soil stays wet; a dry week is not. Give it mud, sand, or muck along a rain garden, ditch, or pond edge, and the leafy culms will hold instead of going crisp. [1] [2] Flowering stems usually stand about three to five feet, with a cinnamon-brown woolly head in late summer. Light shade helps in a hot summer, but the ground still has to stay wet. [3] [4] This is a wetland sedge, not a dry meadow grass, so the ground has to stay wet. Set a new plug on Planting Woolgrass.
Does woolgrass need full sun?
Give it full sun. Light shade is fine in a hot summer, but a dry, dark corner is the wrong site.
How wet does it need to stay?
Keep the ground wet. Wet soil, a rain garden, or a few inches of shallow water is the home. A dry week kills it.
How tall does it grow?
Flowering stems usually stand about three to five feet in wet ground. A small rain garden still needs wet soil the whole season.
Leave the woolly heads through winter, then cut in spring
The woolly heads stay on the stems after frost, and they look good through winter. Leave them until spring, then cut the old culms before new shoots push, so the new leaves have room. Keep the rhizomes in wet ground; do not lift the clump for the house.
- Leave green stems and the brown woolly heads standing through winter.
- Cut the old culms to just above the wet soil in spring, before new shoots show.
- Bag the cuttings so they do not mat back over the new growth.
Do I cut it back in winter?
Leave the woolly heads through winter. Cut the old stems in spring, before new shoots push. Keep the rhizomes wet.
Not cottongrass — and not cattail or a leafless bulrush
Cottongrass is Eriophorum, with white cotton-like heads on nodding stalks — see How to Grow Cottongrass. Tags also say cottongrass bulrush or cotton grass for this sedge; those names still mean the cinnamon-brown wool on woolgrass, not the white bog cotton. Cattail is Typha: flat strap leaves and a brown sausage seed head. Cattail care is How to Grow Cattail.
Softstem bulrush is Schoenoplectus: almost leafless, round spongy stems you can pinch, and small drooping spikelets, not a woolly head — see How to Grow Softstem Bulrush. Garden-center rush in a rain garden is often Juncus, a true rush — see How to Grow Rush. Lawn sedges with triangular stems and leaf blades are Carex — see How to Grow Sedge. Woolgrass is a sedge with real leaf blades and a woolly brown cluster at the top of the culm. Confirm the Latin on the tag is Scirpus cyperinus.
Is woolgrass a sedge?
Yes. It is a wetland sedge, not a true grass and not a true rush. The woolly brown heads are bristles on the seed, not cotton for cloth.
Is this the same as cottongrass?
No. Cottongrass is Eriophorum, with white cotton-like heads. Woolgrass is this sedge, with cinnamon-brown wool. Read the Latin on the tag.
If the leaves go crisp, the ground dried — move it back to wet mud in full sun.
FAQ
Can I grow it in a pot?
Yes, if the mix stays wet. A rain-garden tub that never dries can hold it. A houseplant pot that dries in a day will not.
Will it take over a small rain garden?
Short rhizomes fill a wet shelf. Give a small rain garden room, and do not dump extras into a wild marsh or storm drain.
Is teddybear paws the same plant?
Teddybear paws, marsh bulrush, and cottongrass bulrush are other shop names for this same sedge. They want the same wet sun. White cottongrass is Eriophorum.
What can I plant with it?
Use other plants that stay wet on the same rain-garden shelf, such as How to Grow Rush. Keep the soil wet for all of them.
Related guides
Recommended plants
References
- [1] Illinois Wildflowers -
https://www.illinoiswildflowers.info/grasses/plants/wool_grass.htm - [2] Prairie Moon Nursery -
https://www.prairiemoon.com/scirpus-cyperinus-wool-grass - [3] University of Maryland Extension -
https://www.extension.umd.edu/resource/wool-rush-or-wool-grass - [4] NC State Extension -
https://plants.ces.ncsu.edu/plants/scirpus-cyperinus/
This note is part of Scirpus Guides.
More first-season notes by plant are gathered in How to Grow Guides.
Updated: Reviewed by Bosquelle Editors