We know what's coming. In all but the warmest parts of the country, our gardens soon will be wracked by frost then blanketed in snow, marking the end of the gardening season. Or is it?
If you're smitten by grasses, like Bluestem Nursery's Jim Brockmeyer, you know the value of leaving ornamental grasses standing in the winter garden.
"The winter is so long and so colourless and featureless that anything sticking up above the snow gives interest in the bleak winter and helps define the space," says Brockmeyer, who cuts down none of the grasses growing in his fields in Christina Lake, B.C., in the fall. As well as adding vibrancy and texture, grasses such as switchgrass (Panicum virgatum cultivars) provide protection for pheasants and quail, says Brockmeyer. Another quality of winter grasses that he values is the sound they make. Brockmeyer loves to hear the dry leaves of Miscanthus as they rustle in the winter winds – their sturdy, bamboo-like stalks also make good stakes when cut down in the spring. On large properties, the 10- to 12-foot tall flower spikes of ravenna grass (Saccharum spp., syn. Erianthus ravennae) look particularly impressive in even the deepest snows.
Evergreen grasses are a group that Brockmeyer particularly values for winter interest. The low-growing fescues (especially Festuca idahoensis ) retain their blue colour and stand up to the freeze and thaw cycles typical of some parts of the country, including Southern Ontario. Blue oat grass (Helictotrichon sempervirens) holds its dome-shaped form over the winter, and it's also one of the hardiest (Zone 3), according to Brockmeyer. But with these evergreen grasses he warns, "If you cut them back too deeply into the crown or too early in the spring, then they can be damaged." The safest and most effective way to groom them is to comb out the dead foliage with a leaf rake – the ones with springy tines, he says.
Although they collapse completely under very heavy snows, Brockmeyer loves the look of the tall moor grasses such as Molinia caerula subsp. arundinacea 'Skyracer.' "For that while before the heavy snows come, they look pretty and they dance in the slightest breeze," he says.