Much of East Texas has wonderful moist bottomland forests with tall sweetgums, red maples, and river birches providing dense shade. However, such a situation can create problems if the soil has areas of clay with poor drainage. Most groundcovers, even ferns, do not thrive in such areas, and most ornamental grasses need more sun and drier soils. However, Chasmanthium latifolium, also known as inland sea oats or river oats, might be a good choice if the area is large and natural. It does well in dry shade but becomes a very dense, solid mat in wet shade. In the summer it grows waist high with large green leaves that resemble bamboo, and it has arching oat-like seed heads.
In the fall, the foliage turns yellow to brown and is very showy in mass. You should remove the seed heads in the fall to keep it from spreading; otherwise, you will have a nice crop of seedlings the following spring if the soil is moist. Cut back all the dry foliage in the winter when it becomes unsightly.
New growth begins in late winter if the weather is mild. Cut back the new leaves by half in late spring if you want to keep the height lower. Since it can be invasive, sea oats might not be the best ornamental grass for beds, especially if they stay on the moist side. It can be quite attractive in containers and will survive our winters even if the pots remain outside.
Merlin Eck, Smith County Master Gardener
Texas A&M AgriLife Extension Service