Ornamental grasses have lingered as focal points in the winter landscape with beautiful form, slender leaves dancing with the winds. Until this week, no heavy snow has flattened the maiden grasses. Even cold nights have done little to change the golds of fall foliage to the grays and browns of winter.
When they are still a dynamic component in the winter landscape, it’s hard to cut back any of the grasses. But it is time for many to have their annual trim. If you look closely at the base of the plant, you may even see slender new shoots reaching for early spring warmth and light.
Avoid any damage to the new growth while pruning back the old stalks as close to the crown of the plant as possible. Young ornamental grasses are easily trimmed close to the crown or base with hedge clippers. The older and larger grasses may be tackled with a weed eater. The goal is to leave as little of the old growth as possible without injuring the crown.
Know which plants are evergreen and which are not. All will bloom in the fall, but some will remain green and others will turn gold. Maiden grass (Miscanthus sinensis) cultivars benefit from being cut back each dormant season. If snow has affected their beauty, this maintenance may be done anytime. This year ‘Gracillimus’ maiden grass is still so striking in many gardens, that trimming has been delayed until the last possible moment.
The evergreen maiden grass (Miscanthus transmorrisonensis) may be pruned to the crown, but also may not need to be, especially when the plant is young. Even older specimens in casually maintained gardens may need no attention for years, although it is still a good idea to cut back the flowering portion.
In garden areas of partial shade, I use wild sea oats or spangle grass (Chasmanthium latifolium) in drifts. Some gardeners call this bamboo grass because of its striking similarity to bamboo.
It is a clumping grass but will spread easily from seed. This winter most of the seed is still on the graceful arching stalks. But this week, new shoots are already a couple of inches high, and I will have to be very careful as I trim the clump.
In my wildflower and rock gardens, I trim the basket or deer grass (Muhlenbergia rigens) each winter. If you spot this striking clumping grass along a backcountry roadside, note that no winter maintenance is done, and the grass still looks fine.
Little blue stem (Schizachyrium scoparium) doesn’t have new growth yet. The fine foliage that turned in fall from blue green to shades of apricot and purple has been brown during the winter weeks, interesting with its small fuzzy seed heads. Perhaps I can wait one more week before cutting this beautiful clumping grass.
Native fescues are rarely in need of trimming. It is natural for these grasses to send out new growth each spring, covering the spent foliage, which then becomes part of the mulch under the plants.
Fescues (Festuca) are especially valuable in restoration of soils where tractor activity has left the soil surface exposed. Perfect for erosion control on slopes, there are many fescues that will thrive even in dry conditions, where only seasonal rainfall provides moisture to the roots.
When grasses are cut, the foliage may be left on the ground. Let the birds select what they need for nesting. New growth of the grass may soon cover this material. If the appearance on the ground seems too messy, cover it with some compost, and the soil will be protected and enriched.
And what if the grass looks perfect as it is by winter’s end? Don’t touch it! Sedges (Carex) rarely need winter maintenance.
In fact, Carex species may not recover from a hard pruning. Older plants with a few dead leaves may simply be groomed by combing out the spent foliage. Blue oat grass (Helichtotrichon sempervirens), too, often has leaves that need to be removed by selective combing.
Carolyn Singer has gardened organically in Nevada County since 1977. She is the author of “The Seasoned Gardener, 5 decades of sustainable and practical garden wisdom”, now available locally. She will be a speaker at the Placer County “Gardeners Gathering” in Loomis on March 2. For more information, visit www.carolynsingergardens.com.