Clumping Grasses

Clumping or bunchgrasses, often called ornamental grasses, are a group of plants that we love, and not a single species, or even genus. Clumping grasses come in many sizes and colors, making them a unique and stunning textural garden standout.

Since deer don’t prefer them, they companion well with deer-resistant succulents and perennials.

Ornamental grasses like native Lindheimer and Gulf muhly, and the various pennisetums like purple fountain grass, all have the same clumping habit and require similar maintenance and growing conditions.

They vary greatly in size, so check the plant tag for mature size. Some, like Lindheimer muhly, need lots of room to allow for its at least 3-4 feet height and width. Some pennisetums are tiny and easily tucked into small gardens. Others, like purple fountain grass, get quite large.

Native grasses like muhly are perennial, but others—like the pennisetums—may well be annual, depending on winter temperatures and your microclimate.

They have a shallow root system, so they tolerate various soil types, but their growing areas are at the base, very close to the soil surface, so care needs to be taken that they don’t stay too wet, or they’ll rot.

Most want full sun. For filtered shade under trees, choose soft-leaved Mexican feather grass (Nassella tenuissima). Mexican feather grass easily seeds into preferred areas of good drainage.

Clumping grasses will need to be divided every few years, and need to be sheared to a “flat-top” yearly, depending on each one’s size, back to 6 inches or so from the ground. Shear in late winter, just before new spring growth is set to emerge. That will happen once temperatures begin to warm, so the timing may be earlier or later each year.

They provide swaying, colorful interest in the winter. In late spring through winter, many have colorful seed heads that are soft and fuzzy and reflect the sunlight rather uniquely. Many provide habitat for overwintering butterflies or nesting sites for birds.