Garden Notes: Ornamental grasses can dress up a garden year-round

“A garden without grasses is like a face without eyebrows.” So says William Cullina in his comprehensive book “Native Ferns, Mosses and Grasses.”

He’s not talking about the grass we mow every weekend. That’s a “functional grass” we use to frame our homes and gardens. He’s talking about eye-catching, elegantly swaying grasses.

A garden “sans eyebrows” is a rare sight in Blair County, because ornamental grasses are not just beautiful, they’re almost maintenance-free, drought tolerant and rarely bothered by diseases or pests.

Like perennials, they come in small, medium or large, and a rainbow of colors. Other perennials bloom and then disappear until next year, but ornamental grasses are a fixed attraction that continues into winter.

About now, some of them might be looking a little worse for wear and the gardener’s temptation is to reach for the shears or in some cases, the reciprocating saw. But before you take their life in your hands, consider this. Grasses are classified as cool season or warm season and should be trimmed at different stages in their life cycle.

Cool season grasses like Blue Oat Grass (Helictotrichon) do most of their growing in spring and fall. When the temperature gets above 75 degrees, they endure the heat with good humor and sometimes keep their color, but they don’t put much effort into growing. If you’re a gardener with a cool season ornamental grass, you’ll want to enjoy their beauty through the winter months. As soon as the snow melts, you can cut them back. A word of caution: leave about a third. If you cut too much, you can do irreparable damage.

Warm season grasses originated in the tropics and thrive in scorching sun and high temperatures. Warm season grasses like Morning Light (Miscanthus sinensis) grow best when the temperature is between 75 and 90 degrees. All of them turn brown as cold weather approaches and they won’t green up again until spring.

You can trim warm season grasses back in the fall, but that might be the “cruelest cut of all.” It won’t hurt the plant, but it will rob you of winter interest and relieve you of a quarter of your investment in the beauty of the plant. Wait until spring and you can cut the brown blades back to about 4 to 6 inches. Just do it before the new growth begins.

Annual grasses like Lemongrass (Cymbopogon citratus) or Sweetgrass (Hierochloe odorata) earn bonus points for their beauty and their fragrance.

Clippings are always one of the hardest materials to compost. They take years to break down even if you run them through the shredder. You can speed the process by putting them in a pile, burning them and adding the resulting ashes to your compost pile. But first, check your local ordinances. It’s easier to haul the clippings to a composting site than it is to pay the fine.

Contact Teresa Futrick at