Ornamental grasses like maiden grass (Miscanthus spp.), feather reed grass (Calamagrostis x acutiflora), fountain grass (Pennisetum spp.) and switchgrass (Panicum virgatum) have become popular for the winter interest they add to our gardens. Even though they lose their summer greenery and turn various shades of beige and brown in the autumn, still they stand upright over the winter, waving their silvery plumes in the air, for a striking effect, especially against a background of snow.
This is great when it works … but it doesn’t always. Sometimes they are flattened by the first winter storm and spend the rest of the season lying on the ground. Of course, you could stick a piece of rebar into the center of the clump and use garden twine to pull them back up … but the effect is rarely as nice.
To avoid this completely, remember that these grasses are usually native to spots fully exposed to sun and wind: prairies, meadows, steppes, etc. If you plant them in a partially shady spot or one protected from the wind, they develop thinner, less robust stems subject to flopping. Grow the same grass out in the open, though, and their stems will be thick and strong. This comes from being exposed to burning sun and from being constantly pushed back and forth by the wind starting early in the season. The plant’s reaction to this “punishment” is to add extra lignin to its stems, resulting in a tougher, windproof grass.
So if your grasses flop in the winter, try moving them to a more exposed site next spring and next’s year’s show will be spectacular!