Growing Chasmanthium
Latin Name Pronunciation: chaz-man' thee-um
Chasmanthium is a small North American genus of Grasses represented in the horticultural trade by C. latifolium, an attractive, warm-season clumping, native Grass from woodland, floodplain, and stream bank habitats. It grows in dry to moist soil and in sun to shade. A propensity to self-sow in moist fertile soils makes it ideal for establishing wildlife habitat, as a tall groundcover, or for erosion control. Gorgeous as a specimen or small drift in a neat and tidy garden, some attention is required.
Growing Chasmanthium
Plant the crown just at soil level, or slightly above if you will be adding mulch. Spacing is indicated on the back of the plant tag. Will naturalize by self-sowing in moist fertile soils. If seedlings are unwanted, remove as soon as they appear. Tenacious, short, rhizomatous roots are ideal for erosion control but somewhat difficult to remove when mature.
Light: Full sun to part shade, one of the most shade-tolerant native Grasses.
Watering:Medium to low water needs. Prefers moisture but tolerates drought
Fertilizer:None required. Mulch with previous season’s dried foliage, leaves or shredded hardwood bark. Application of compost from decomposed leaves will contribute to resilience and drought-tolerance.
Soil:Best in fertile, moist, woodland soils, but adaptable to well-drained dry soils or poorly-drained clay.
Pests/Diseases: Generally pest- and disease-free, although voles may feed on crown.
Dividing/Transplanting: Does not usually need dividing, but if you wish to increase plants by division or move them, dig up the entire clump with a sharp sturdy spade and cut into sections for replanting or pull apart by hand. Dividing and transplanting are best done in spring when plants are actively growing, but may be done when plants are still dormant; this is one tough plant.
Early-Season Care: Cut back old foliage to a few inches; it can be chopped up and strewn as mulch. Look for self-sown seedlings, which begin growing from short rhizomes in late spring. If unwanted, dig them out while small, and, if desirable, replant them in another location.
End-of-Season Care: Chasmanthium foliage, with or without seed heads, is attractive in winter. We encourage you to refrain from cutting plants back in fall, as they provide habitat and food for numerous birds, beneficial insects, and animals, and will enliven your landscape with sound, texture, and the uplifting sight of dangling seed heads. If some stems are knocked askew after storms, judiciously snip them for dried bouquets. Otherwise, although you can cut clumps back when they turn brown in fall if you simply must, we prefer to wait until spring to chop foliage down to a couple inches and use it as mulch. If self-sowing is not desirable, deadhead or make a bouquet for indoors when seeds are ripe (they will be brown).