Monday, May 10, 2010

Native Ground Covers - Part 2

In the last post I listed some of the herbaceous and small woody native plants that I have been using as ground covers. Sometimes you want that grassy look. There are a number of options for low maintenance grasses as alternatives to the Non-Native Kentucky Blue Grass and Perennial Ryes commonly used in residential lawn grasses.

One option to the conventional lawn is the use of fine fescue grasses.  These have a silkier appearance and tend to be a lighter shade of green than KBG.  Two commercially available seed mixes based on blends of fine fescue grasses are ‘No-Mow’ Mix from Prairie Nursery and Eco-Lawn from Wildflower Farm. These mixes contain a blend of creeping and clumping fescues, some of which are native to North America, which will tolerate a range moisture and light of conditions. Lawns of these grasses are reported to require very little mowing (1-4 times/year), little additional water and no fertilization.

Another option is to do a sedge lawn. Sedges, members of the genus Carex, number about 2000 species world-wide, with about 480 representatives native to North America. With so many species, there are some that are adapted to nearly any growing condition. In general, they look like average grasses. This genus can be distinguished in that sedges have triangular, not round, stems. When viewed down the stem the leaf blades radiate off at 120-degree angles. Sedge lawns are a better choice for wet conditions than fescues, however they do not tolerate foot traffic as well. Brooklyn Botanical Garden has a useful article on sedge lawns.

The first sedge that I became intrigued with was Rosy Sedge, Carex rosea. I saw this ‘in bloom’ in a friend's yard with its tiny (~1/8th inch) rose or star-like, tan colored inflorescences. These come in late spring. Otherwise, it just looks like grass. Unfortunately, I do not have a photo or these little flowers at this time, but here’s what it looks like without them. While it is naturally distributed over the eastern 2/3rds of the U.S., I do not know of a commercial source for this sedge.

Since first seeing Rosy Sedge, in 2006, I have become more interested in these plants. Two sedges that are available and well adapted for use in the Northeast are Pennsylvania Sedge (Carex pensylvanica) and Appalachian Sedge (C. appalachica).

Appalachian Sedge forms clumps with mid-green blades 8-24” long. These clumps do not produce rhizomes. The bloom time is in late spring, with seeds forming in late spring to early summer. Its native habitat is in dry to mesic deciduous forests and its native range includes the eastern states from Georgia to Canada. In my yard I have it growing successfully under a Sycamore Maple (another invasive tree). The foliage turns tan over the winter, but it greens up rapidly in the spring.

Pennsylvania Sedge is becoming much more available in the nursery trade. It is a little smaller than Appalachian sedge, with leaves at 4-18 inches. It is reported to tolerate occasional mowing (I haven’t mowed mine yet on purpose, anyway). Also it does spread slowly by rhizomes, a good trait for a lawn grass. The inflorescences appear in early spring as dark brown spikes, just above the foliage. These come before and are easily distinguished from the flowers of Appalachian Sedge. This sedge is found in well drained acidic, but rich soils in and along hardwood forest edges and openings. The native range includes the eastern states from Georgia to Canada to just west of the Mississippi River. My Pennsylvania Sedge is also doing well under the same maple tree. Mine is a bit larger than the Appalachian Sedge, but it has been in the ground a year or two longer. For me the beauty of both of these grasses is that they do well in DRY SHADE!!!

For more general information on growing alterative lawns check out the following links:
>Planting a ‘No-Mow’ lawn. This link also has a clear and concise statement on growing/encouraging moss.
>Native Grass Lawns: Lots of information on a variety of altenatives
>Planting a Native Grass Lawn. This is another useful link for the Brooklyn Botanical Garden site.
The book, Easy Lawns, edited by Stevie Daniels, gives information on growing low-maintenance native grass lawns appropriate to each region of the U.S.

1 comment:

Curbstone Valley Farm said...

Very interesting post. Now I feel like I'd be better able to identify any sedge we may have growing here. I hadn't realized about the triangular stems.

We have been looking into sourcing some Berkeley Sedge (Carex tumulicola) for around our orchard area. We saw some on a recent native garden tour, and the mounds are pretty, but not so tall as to hide our native wildflowers on the slope. We just have to try to keep our invasive brome grasses in check while it gets established.