Top Native Sedges for Lawn Replacement
This is an exciting time for sedges. More and more of them are becoming commercially available, as more of their benefits are known and appreciated. They hit so many of my own plant selection checkboxes: tremendous wildlife value, good winter interest, and suitable for a wide variety of site conditions (if you know which ones to select). They come in a variety of heights and interesting textures, some of them make great groundcover, and they are super low maintenance. So, yep—these are definitely powerhouse plants in the world of native plant landscaping!
In this article I’m going to write about sedges as a lawn replacement. But clumping sedges are also great as garden elements, so I hope soon to write about using sedges in the garden, as well.
In Mt. Cuba’s recently completed trial of sedges (the scientific name for these plants is Carex), one of the evaluations made was for carex’s use as lawn replacement. I want to share with you the top 3 performers in this category, and tell you how to go about creating your own very low maintenance sedge lawn.
How is wildlife supported by native sedges?
Sedges are host plants for a variety of butterflies and moths--meaning that the leaves are necessary to caterpillars that will eventually become butterflies and moths. Sedges also provide important habitat for toads, frogs, and turtles. And the seeds of sedges feed small mammals and many birds.
Any maintenance required?
One of the great features of sedges in the landscape is their ease of maintenance. If you are in an ultra tidy area, such as the front of the house, you might give them a late winter or early spring cutback, but this is only if desired for aesthetics, and is not required for the health of the plant.
For a lawn-like look, carex can be mowed as often as every 2 weeks from May until late August, using a generous 4” blade height setting on the mower. But if your lawn replacement just needs to be short and doesn't have to look like a lawn, even this is optional!
The top 3 sedges for lawns in our area:
Carex woodii (Wood’s sedge) is a spreading rather than clump-forming sedge that develops dense mats when mowed, remarkably in both sun and shade. Fine-textured foliage emerges blue-green and changes to green later in the season. Texture and habit are similar to the very popular Pennsylvania sedge (Carex pensylvanica) but it forms a denser and more weed-suppressing mat.
Carex eburnea (bristle-leaf sedge) has an ultra fine texture and grows in low, mounding clumps that expand over time. This is an excellent choice for dry shade. I am looking forward to mixing this in on a dry, fern-covered slope that I don’t mow, but that needs more cover to keep the invasives out.
Carex socialis (low woodland sedge) is a good choice for a sunny area. Mt Cuba reports that this plant was weak without mowing but bounced back “with surprising vigor” when mowed, and formed “dense, impenetrable clumps that would be the envy of any turfgrass enthusiast.” Wow, in full sun. So interesting!
How to convert your lawn to sedge
If you are replacing an existing lawn, you will need to kill whatever remains of the lawn (and any dormant lawngrass seeds) that were there. The two best ways to do this are to smother the lawn with a layer of newspapers and mulch, or to cover with tarp and then remove the tarp after 2-3 months. (Yeah, this takes a little planning ahead!) For details you can read about lawn alternatives on the Univeristy of MD website.
For planting, you will have to decide whether to use plugs or seed. Basically the decision amounts to balancing two concerns: cost vs speed of establishment. Plugs are easier and speedier to establish. But if you have a large area, the cost of plugs might be prohibitive compared to seed.
What about foot traffic?
This is really the elephant in the corner, when it comes to lawn replacement research. Mt Cuba handled this by…hmmm, well actually it turns out they didn’t study this at all!
Here is my current and ever-evolving take on what to do for an area that has to handle foot traffic. The sedges alone probably won’t cut it. But they don’t have to, if you can work in stepping stones or wood decking planks or some other way to navigate through the area.Another idea for light to medium traffic is to mix in other plants that can handle some light traffic to help fortify the sedges.
Depending on the circumstances, you might try the shortest kinds of violets (E.g. viola labradorica), or tough lyre-leaf sage (salvia lyrata), or the invincible wild strawberry (Frageria virginiana).
Finally, if it really has to handle heavy traffic, for frisbee, dogs, and kids, you might just allow that area to be in traditional lawn and make your difference by putting natives into beds that surround that hopefully-now-smaller lawn area.
If you want to read the full Mt Cuba report, you can find it here. They have some good photos of each sedge in their trial (and they trailed all of 70 sedges! I just love this place...). Please, if you have tried any of these sedges for lawn replacement, I'd love to hear from you! How is it going so far?
And of course, if you’d like a consult visit to plan your spring planting, this is an excellent time to get on the schedule before things get busy. Read more or send me a note at my website to get on the schedule early.
Happy Planning!
Chris