I’ve developed a bit of an obsession with ornamental grasses over the last few years, and Northern Sea Oats (Chasmanthium latifolium) is one of my favorites. Happily, it’s also very easy to grow here in Michigan.
About Northern Sea Oats
Northern Sea Oats are perennial, and form upright plants, with very attractive arching foliage, about 2 to 3 feet tall. Seedheads appear in mid to late summer, and turn light brown in late fall. One of my favorite things to do in winters is stand in the garden and listen to the seedheads rattling in the breeze. I like to leave mine standing all winter to add interest to the garden, and then cut it down about 4 inches above the soil’s surface in spring.
Northern Sea Oats spread via rhizomes and by seeds. Some gardeners find it invasive. If you’d like to prevent it from spreading in your garden, cut off the seedheads in early fall, before they turn brown and start falling from the plant.
Plant Northern Sea Oats in partial shade to full sun. If you plant them in full sun, the foliage is lighter in color — they seem to prefer partial shade. They’ll tolerate heavy soil (a benefit, since I have so much clay in my soil!) and prefer things on the moist side, though they will withstand some drought. I don’t do any fertilizing, other than my annual topdressing of compost in early spring.
Northern Sea Oats are hardy in zones 3 to 9.
This is an easy-to-grow plant that adds plenty of interest to your garden. It’s easy to grow from seed, and is also available in most nurseries and garden centers. If you’re looking for an ornamental grass for your garden, Northern Sea Oats is a good one to add!

