In Part 1 of this discussion of ornamental grasses, we talked about grasses for part-sun, for cold climates, and those that provide fragrance. Today we’ll cover grasses that provide fall and winter interest.
Blades of Color
The most common fall color for grasses is a warm tan, but there are also some that are as bright as autumn leaves. Plant them where they’ll show up: the pale ones backed by dark evergreens, stronger shades where they will blaze against the pebbles of a courtyard or an open sky.
Yellows include many of the molinas, especially Molina caerulea cultivars, and Phragmites australis.
Shading more toward orange and red are the big bluestems (Andropogon gerardii) and switch grasses (Panicum virgatum), especially the variety ‘Haense Herms.’ Indian grass (Sorghastrum nutans) does double duty, starting out yellow and shading toward orange as the season progresses.
For darker reds, consider Miscanthus sinensis ‘Graziella’, which has warm brown undertones, the purplish Hakonechloaa macra; Imperata cylindrica ‘Rubra’; and Miscanthus sinensis ‘Purpurascens.’
The best grasses for winter interest are those that are quite sturdy, able to stand up to rough weather, including the feather reed grasses (Calamagrostis spp.), Ravenna grass (Erianthus ravennae), little bluestem (Schizachyrium scoparium), and those that have decorative seed heads, such as Indian grass (Sorghastrum nutans) and cat tails.
For the prettiest effect, they should be planted in groups of varying heights of where they will be set off by evergreens, garden sculptures, or other structural elements that give them a context. If you just dot them here and there, they tend to look like something you forgot to clean up.
Cutting Grasses Back
In nature, nobody cuts down grasses, so why should we? Well, in nature, the open areas where grasses grow are periodically renewed by the cleansing effects of fire. In the absence of this very efficient remover of dead material, we need to cut back our grasses.
The best time to do it is in early spring, after the grasses have done winter landscape duty but before the new growth starts. Wearing gloves (many grasses have sharp edges) and using hedge clippers if the clumps are large, cut off the dead stalks right above the ground. This will not only open up the plants, bringing light and air to the centers and thus forestalling disease, but it will also remove a potential fire hazard.
Note: Grasses will let you know they need division by flowering less and/or dying out in the center of the clumps. Be on the alert for the start of these symptoms and divide the grasses then. You want to get in there before things get ugly, but there’s no need to divide plants that show no signs of needing it.