Can I cut back ornamental grasses now?
The foliage of ornamental grasses is usually enjoyed throughout winter. Traditionally, it is cut back just before new growth occurs in the spring. The exception would be miscanthus, which self-seeds, making it invasive (usually the seed-grown or early-flowering varieties.) Cut these seed heads off in fall. Any other grass whose seed is becoming a problem for you can also be cut back early to prevent self-sowing. Cutting huge old clumps of ornamental grass can be an onerous job. Some gardeners use a bungee cord to encircle the stems tightly, then cut them with a chain saw or electric hedge clippers.
A maverick root is growing across the base of my maple tree. Is this a "girdling" root that can strangle the tree eventually? Can I cut it off?
Removing it depends on the size of the root. When the girdling root crosses the base of the tree and the trunk above is already flattened with no normal flare, then the root is probably too mature to be cut. If the tree is young and the root not huge in proportion to the tree, you may be able to cut it. Do so as soon as possible. The longer you wait, the more traumatic its loss will be for the tree.
Maples are especially prone to girdling roots. To avoid girdling roots, dig a planting hole wide and, especially in heavy clay soils, when soil is not wet. You don't want the roots to go around and around in the hole. Set bare root plants in their holes and carefully fan out the roots, radiating away from the trunk. For containerized plants, wash soil off the roots so you can clearly position them as just described.
University of Maryland Extension's Home and Garden Information Center offers free gardening and pest information. Call 800-342-2507 or send a question to the website at hgic.umd.edu.
Plant of the week Winter aconite, Eranthis
Winter aconite, a native of Europe, is in the same family as the buttercup but, unlike its cousin, its yellow cup-shaped flowers are large. Another more colorful, literary name for it is wolf's bane. All parts of the plant are poisonous to humans. In spite of its reputation, the plant is highly prized among those who have a wooded or shady area in need of ground cover that blooms early in the spring but can go dormant in summer. While the rewards of a successful planting are great, this plant is not for the casual gardener. Try it if you have a deciduous wooded area, rich in organic soil that doesn't dry out too much in summer — or a neighbor you suspect of being a werewolf. Where happy, eranthis will form colonies. Plant in fall. When ordering from a distant supplier, place it in the soil as soon as it arrives. The tubers do not like to be stored. —Lew Shell