Lawn alternatives in shady areas
Q: I’m happy to try a lawn alternative for my shadier areas, but I’d like it to look more like a lawn than a ground cover or mix of flowering plants. What kind of grasses work for that? A:
Not many true grasses if you have less than full sun, but several perennials that look like grasses can work nicely. My primary recommendation would be to try one or more species of sedge (Carex). I was excited to see the study results for sedges released recently from Mt. Cuba Center.
The report “Carex for the Mid-Atlantic Region,” the result of a four-year evaluation of multiple Carex species, may be a useful reference.
Mt. Cuba Center is a public garden and research facility in Delaware that displays and studies native plants. The center performs periodic plant trials to evaluate species and cultivars for garden performance.
Lately they have also been including an assessment of pollinator appeal, though in this particular case, that wouldn’t apply since sedges are not grown for that purpose. (Even though the caterpillars of several of our less-oftenseen butterflies feed on sedges.)
Well over 100 sedges are native in Maryland, and the Mt. Cuba study results include lists of those well-suited to more sun than shade, more shade than sun, and a tolerance
to mowing (not that they require it by any means).
A few true native grass species tolerate some shade, but won’t give you a comparable look to a lawn since they grow much taller or have a different leaf color or texture (often wider,
coarser leaves).
Examples include River oats (Chasmanthium latifolium) and Eastern bottlebrush grass (Elymus hystrix), which still could make nice accents if you wanted spots with showier seed heads.
The nonnative asparagus relative mondo grass (Ophiopogon), which has dark green grassy evergreen leaves and a slowly-spreading growth habit, has been successfully grown as a lawn lookalike under mature trees.
I would not recommend using its cousin liriope, the spreading form of which (Liriope spicata) can be too aggressive and is considered invasive. (Plus, it’s way over-planted.)
Mondo grass thus far does not appear to be colonizing natural areas in or near Maryland.
Q: I’ve heard that I shouldn’t dig when the soil is “not workable,” but I don’t quite grasp what that means. I get that being too squelchy-wet is a problem, but how do I tell when it’s dry enough? A:
I like using what I think of as the “snowball” test. Grab some loose soil from a test dig and form a soil “snowball” in your hands. Don’t pack it too tightly; just press firmly enough to get it to form a shape. Then, let go and just hold it in one hand and either prod it gently or carefully toss it between hands like you’re juggling. If it crumbles or breaks apart easily, it’s probably good to go. If it remains dense like you’re trying to go bowling with it, or splats to the ground as a muddy mess, it’s too wet.
If it never holds a shape to begin with, then maybe it’s fairly dry or just too sandy to use this method. In that event it may benefit from more organic matter incorporated or top-dressed over time to help it bind together more, since this will also impact its moisture-holding capacity and nutrient retention. If in doubt and it has rained recently, it shouldn’t hurt to just give the soil more time to air out again.