"That's Penn Sedge? I thought it was grass!" Penn Sedge growing naturally among a native Potentilla groundcover, Common Cinquefoil (Potentilla simplex) that is not yet in bloom. Photo credit: TBeckjord
The soft fall of the leaves of Common Oak Sedge (Carex pensylvanica) is so much more attractive and so much more enriching for the soil than mulch, and it even grows in dry shade! Photo credit: TBeckjord
The rich lime green of the Palm Sedge (Carex muskingumensis) contrasts beautifully with the blue-green of what is probably Carex flacca. Photo credit: TBeckjord
Seedheads of Gray's Sedge (Carex grayi) provide an interesting accent against the leaves of Sensitive Fern (Onoclea sensibilis) at the edge of a pond. Photo credit: TBeckjord
In contrast to more finely leaved sedges, the coarser texture of Plantain-leaved Sedge (Carex plantaginea) makes a statement in the shade garden when planted en masse! Photo credit: TBeckjord
This Brown Fox Sedge (Carex vulpinoidea) was mistakenly planted among Prairie Dropseed. While appearing similar in habit, it grows faster in the spring and significantly contrasts in size with the Sporobolus around it. This sedge is a good rain garden choice. Photo credit: TBeckjord
Rosy Sedge (Carex rosea) and Star Sedge (Carex radiata) are difficult to tell apart without a microscope. This is Star Sedge. Both are low- growing and finely textured. Lovely additions to the shade garden! Photo credit: TBeckjord
A Love Affair with Sedges
I can’t remember when I first fell in love with sedges. After all, doing such a thing is probably not a memorable event. Perhaps I just started liking them more and more once I got to know them better. I’m like that with a lot of things. Plants for sure, food, a certain book… Haven’t you all at one time or another said something like, “…I don’t know. I couldn’t get into it at first, but keep at it. I loved it at the end!” Loving sedges is a bit like that for me although I didn’t have to work at it very hard.
To many of the uninitiated, sedges just look like grass. In fact I have a very good friend where it took multiple visits and multiple times, and even multiple years of my ooo’ing and ahhing over Pennsylania Sedge (Carex pensylvanica) and pointing it out in her oak woodland before she stopped saying “Oh, that’s Pennsylania Sedge? I’ve been pulling it; I thought it was just grass!” Rest assured, she gets it now and can identify it on sight.
So what’s to love you might ask, and how do you tell if you have a sedge? The secret to the second half of this question is pretty simple; “sedges have edges; grasses are round.” The edges of the triangular cross-section of a sedge stem (or culm for you Scrabble players out there) are pretty easy to feel. It is perhaps easier on some of the larger stemmed species, such as Carex stricta, but the edge is quite clear even on smaller, more delicately-leaved species, such as Rosy Sedge (Carex rosea).
I will be the first to tell you I am not a sedge expert - these guys are darned hard to identify and there are quite a few of them. Differentiating between species often takes a microscope! But you don’t need this level of expertise to include some interesting sedges in your garden, and this is where we get to the “what’s to love?” question.
Containing approximately 2000 species and having a broad ecological range, the genus Carex is one of the largest, most diverse group of flowering plants in the world. Most of our sedges in the northeastern Illinois/southeastern Wisconsin region are either woodland or wetland species although there are exceptions. In size they range from small ( 4” to 1’) to more than five feet high. Some grow in drier soils such as may be found in oak woodlands while others prefer wet soils and even standing water. As a result of this broad variety, sedges are an important contributor to plant/habitat diversity.
The variety offered through their leaf and seed structure is also horticulturally attractive in many species. If you google “how many sedges in Illinois”, one of the links that comes up is an absolutely fabulous pictorial identification guide called Carex of Northeastern Illinois and Northwestern Indiana, USA Sedges (Carex spp.) of the Chicago Region.
As with other species, the Japanese sedges were the first to hit the U.S. horticultural market, and a number of selections are still popular. Examples include Carex morrowii ‘Ice Dance’ and ‘Silver Scepter’. Another is Carex oshimensis ‘ Evergold’ and the variegated cultivars ‘Snow Cap’ and ‘Banana Boat’ of Carex siderosticha. All of these are species of Japan and other east Asia locations, but I’m pleased to say our very own native sedges are also becoming more popular outside of the ecological restoration market.
Sedges in general provide a food source, habitat and protective cover for a variety of insects, birds and other mammals. Dependent upon the habitat, this includes the caterpillars of several moths, skippers and butterflies among other insects as well as other beetles. In addition to supporting insectivorous birds, the seeds of sedges support a wide variety of birds including wild turkey, ducks and various songbirds as well as other small mammals. Their root systems are densely fibrous which not only helps hold soil but also adds organic matter to the soil and helps keep it open and absorptive of water.
Among others, consider some of these wonderful sedges for your garden:
Carex pensylvanica Penn Sedge, Pennsylvania Sedge, or Common Oak Sedge A finely leaved, low-growing sedge (+/- 1’ tall) that will grow in dry shade but prefers some leaf litter; grows in loose clumps and slowly spreads by stolons. Has been used as a turf substitute. I love the delicate character of this little sedge!
C. muskingumensis Palm Sedge A medium height sedge (up to 3’) whose clearly 3-ranked leaves reflect the characteristic triangular sedge stem. Will spread to form colonies but is not overly aggressive. Prefers a moist, loamy soil and partial sun. Can be found in swampy conditions in the wild but grows successfully in average garden conditions. A variegated cultivar ‘Oehme’ is also available.
C. grayi Gray’s Sedge A more robust sedge that typically grows to 2-2 ½ feet. Likes moist-wet soils and is perfect for pond edges. In the wild grows in woodlands and wetlands. Will spread by roots. Tolerates standing water. The seedhead is an eye-catching ornamental feature! I have seen this sedge growing in standard garden conditions.
C. plantaginea Plantain-leaved Sedge Another shorter woodland sedge (+/- 1’) sedge whose broad leaves look a bit like seersucker. Will form tight clumps from short roots. Like ferns, with which it associates in the wild, this sedge prefers a consistently moist soil. Don’t you just love it!
C. vulpinoidea Brown Fox Sedge Will grow to 1 ½ to about 3 feet tall although I’ve typically seen it no taller than 2’ in garden conditions. A wetland sedge that prefers full to part sun and wet to moist conditions. Another great candidate for the bottom of a wet swale, pond or lake edge. Tolerates temporary flooding.
C. rosea /C. radiata Rosy Sedge/Star Sedge Two short, finely leaved woodland sedges that look almost identical and are very fine of leaf. Will form dense clumps to no more than 1 ½ ‘ tall; prefers a nice loamy soil with good organic material and soil moisture. Is not rhizomatous. Provides a nice textural contrast to hostas, ferns and other species.
I hope you take the sedge plunge and learn to love them like I do. Happy planting!