What are Sedges and Why Should I Plant Them?
I didn’t know sedges existed until just over a decade and an half ago when my son introduced me to that world. I probably just had plant blindness* around sedges, because they are everywhere!
Sedges are graminoids along with grasses and rushes. Graminoids are usually defined as grass-like plants. Leaves are linear. They typically have fibrous roots. Sedges, grasses and rushes have some common morphology beyond those characteristics, but I will leave it there for now.
Sedges, in general, are in the genus Carex. The genus Carex is one of the largest in the world with 2000 species worldwide. There are 500 species in North America and in Michigan we have just over 180 species, including some that are adventive either from other parts of North America or from Eurasia.
Sedges grow in just about every environment you can think of. They grow in sunny, dry places, and in wet, even submerged, places. They grow in moist meadows and they grow in the forest, sometimes in dry forests and sometimes mesic or wet forests. They grow on shorelines, bogs, fens, and prairies. Bogs and fens, in particular, have a lot of variety when it comes to sedges.
Some sedges are just a few inches high, while some may reach six feet high! Many are in the range between 18 inches and three feet.
The main way to differentiate sedges from grasses and rushes is the fold down the center of the leaf, making them V-shaped. Young leaves can be M-shaped.
The next thing to observe is usually the inflorescence whether the plant is in flower or in the seed stage. Sedge seeds are surrounded by a sac, kind of like a balloon in some species, more of a covering on others, which is leaf-like. The shape, size, arrangement, and sometimes color of the perigynia are all important in making correct identifications of them. If not in flower, or seed, identification becomes a lot more difficult, maybe even impossible.
Beyond that, there is a whole list of other characteristics that may be important in order to use the Carex key in Michigan Flora, or just to learn so they may be recognized in the field. These things include: leaf width, height of the plant, the color of the base of the plant, the leaf sheath, placement of various bracts, arrangement of male and female flowers, habitat and more!
Sedges are divided into sections of species that have a lot of common characteristics. This can be quite helpful because if you can narrow things down to the section, that is a much smaller portion of the key to focus on.
So there is a little bit about what a sedge is, and now, why should you plant them?
First off, and this is purely selfish, they are often gorgeous plants. They come in a variety of greens, heights, arching stems and leaves, dangling or upright groups of perigynia, etc.
Next, some have been tested as lawn replacement. You can learn more about that by reading about Mt. Cuba’s sedge trials. There is a lot being said these days about the uselessness of the lawn, drinking too much water, being covered in toxins, and being habitat to almost nothing. However, some still like the lawn look. Replacing it with sedges where possible is one solution.
Finally, sedges provide essential ecological services.
Graminoids, including sedges, are often the first plants that return to an area after disturbance including fires, floods, construction, pollution and more. With their fibrous roots they stabilize the soil to hold it in place. Soil is a valuable resource, but it can be lost. The way this happens is when there is nothing planted and it is either washed away with precipitation/flooding or blown away by the wind.
I took the lawn out of the parkway by the road and planted grasses along one edge and ivory sedge along the other edge in the hope that it will keep foil from being lost onto the sidewalk, which has been a problem in the short term.
Sedges roots provide support for other plants as they begin to establish.
Sedges are great plants for providing shelter for small animals and insects, places to hide, and places to live, including nesting underground or on the ground.
As a ground cover they also shade the soil and keep it cool, which is a requirement for the roots of many plants.
Sedges are the host plant for some moths, skippers and butterflies. Many of these species can use any sedge species as host.
Sedge seeds provide food for birds and small mammals.
Sedges are a natural part of ecosystems and are important for reasons we may not yet understand.
So, instead of mulching year after year (which over time actually damages the soil), consider adding sedges as green mulch, which will help the soil you currently have and even help build soil! This is called matrix planting where the sedge is the background with groupings of other plants and then a couple of dramatic species here and there.
Replace a portion of your lawn with sedges and/or other short plants that will support a variety of wildlife.
Add sedges just for the dramatic look of some of them providing contrast in the garden.
Add sedges so that over time you can learn something new! I recently saw an article about how birding changes the brain. The effect is similar to learning a new language or learning to play an instrument. I’m guessing that deep dives into botany are much the same!
If you visit the shop, I’ve included handy information about each species, plus photos. I’ve often included a note about why they are generally important their descriptions, such as what I’ve shared above. If you have any questions about a particular sedge or how to incorporate it into your garden or project, shoot us an email at info@wildgingerwoodlands.com
There will be more sedges added in the future!
Do you have a favorite?
*Side note on plant blindness:
I went on a backpacking trip with a friend. It was hard for me to keep my eyes on the trail because I was constantly scanning for plants. I remember having a short conversation about it when she told me that they all look the same to her. I was stunned, but all of us have blindness to certain things. I remember a time when I didn’t know much about plants at all (Zoology major), and might have said the same thing!