Carex Ideas for Dry or Wet Gardens

This issue:  Sedge (Carex) combinations for low maintenance care.

Do you have enough sedges in your landscape yet? Is such a thing even possible? (Yes, I’m that crazy about sedges.) What other group of plants gives us so much? Most are semi-evergreen and deer tolerant, they make good groundcover, offer great support for wildlife, and have root systems that can help prevent erosion. Plus they come in all sizes and characters—from a tall, spunky, superfine spray to a flat, crinkled ground-hugger…Lots of fun to design with!

I’m still enjoying drilling deep into the recently released Mt Cuba report on sedges. Since there were 70 sedges evaluated—65 species and 5 cultivars—there is a lot to digest. (If you missed it, here is a link to my previous article about sedges suitable for lawn-like situations.)

The 24-page report begins with a section of excellent photos and descriptions of the 15 top performers who excelled in the average soil conditions that are present at the Mt Cuba trial garden site. So for those with average garden soil—here is the link (go straight to page 8).

But later on in the report there are two lists that I think could be helpful to those of us who do not have average soil, but are challenged with the extremes of dry or wet garden conditions. 

Since I often help clients select sedges, I am writing up descriptions of my favorites from those lists, or those I think would be worth trying. (That is actually how a lot of inspiration for these newsletter articles happens…) So here is a more detailed treatment of 6 top garden sedges from the trials, that might be useful in small or large garden settings—3 for dry and 3 for wet gardens.

All of these 6 sedges are semi-evergreen, which means that they tend to retain their green leaves through much if not all of the winter. There might be a little browning at the edges as winter wears on. I've included some plant combination suggestions also, since that's an interest I hear often.

DRY GARDEN SEDGES:

Carex eburnea/Bristle leaf sedge (small, shade, semi-EG) Very delicate, superfine texture but actually the plant is tough as nails, holding its own against drought and root competition. Grows in short, slowly expanding clumps. (Was also featured as a lawn alternative option). I have a drift of these holding a slope in a dry sandy bed beneath a Post Oak--pretty tough conditions. Deeper along where the slope flattens out I have Penstemon hirsutus/Hairy beardtongue and Polemonium reptans/Jacobs ladder (shown in photo in early spring).

Carex leavenworthii/Leavenworth’s sedge (medium, sun or shade, semi-EG) Leavenworth’s sedge is taller and forms a relaxed, soft effect in a garden. Not quite as fine-textured but still very narrow blades. The late April blooms are lovely, light green. Then the bloom stalks fall to the ground followed by new growth emerging to make the plants fuller again. It would be interesting to try these in front of a grouping of Itea virginica/Virginia Sweetspire.

Carex texensis/Texas sedge (medium, shade, semi-EG) This petite, spikey-looking sedge can add a bit of attitude to a dry shade garden. Although Mt Cuba lists it as clump forming, other sources emphasize its moderate growth by rhizomes (and to be fair, these two characteristics are not mutually exclusive). One source promotes this short carex as having some tolerance for light foot traffic, and my experience with it here in Annapolis bears this out. Makes a soft green substitute for a gardener's stepstone path.

WET GARDEN SEDGES:

Carex bromoides/Brome sedge (shade or part shade, medium, semi-EG) Clumping, but average size was 16”h x 33” w in the trials. Blades are described as flowing and fine-textured. If you dislike things that look floppy, you might not like Brome sedge—it looks very relaxed! Can be divided in spring or fall. I think this soft, flowing texture would contrast well with other damp shade-loving pants—in a large area I might try Conoclinum coelestinum/Blue mistflower and Spigelia marilandica/Indian Pink (and then watch for hummingbirds!)

Carex grayi/Gray’s sedge (shade or sun, large in size, semi-EG) Plant this one for its spikey, mace-like seedheads of striking pale green. Mt Cuba states that this one was the most-talked-about plant in the garden. An excellent addition to rain gardens and other damp places.

Carex socialis/Social sedge (medium, shade, semi-EG) This would be perfect for a deciduous woodland garden, set under some trees amongst ferns and perhaps some mertensia virginica. This sedge is listed as both clump-forming and rhizomatously spreading. Meaning it could be used for a garden setting, but also did well when mowed.

Do you have any opportunities for some of these sedges in your landscape? I'd love to hear how it goes!
Happy Gardening,
Chris