My friend offered me extra plants from her yard. She said they are pretty but spread a lot. I'm a little nervous about accepting them. What do you think?
Beware pass-along plants when a friend says they are indestructible, spread fast, and outcompete other plants. If you hear "Nothing kills it!" that can be a recipe for disaster. (When the plant is not native, it's a perfect description of an invasive plant.) You don't want to be fighting these plants for years to come. Many plants will spread or reproduce in the landscape when they are happy — and that's great — yet most do not get out of control. You don't see azaleas taking over the neighborhood! So do a little checking (you can call, email or send us a digital photo) before you put the free plant into the ground. That said, pass-along plants may become prized mementos of treasured friendships for years to come.
A bunch of flies are stuck to the new tips of my baby dogwood. Are they hurting it? They don't seem to be moving.
The flies are victims of a silent killer. They are the adult life stage of the seed corn maggot. Normally these insects overwinter underground in the pupal stage, then the flies emerge, mate and lay eggs in soil. The larvae hatch and feed on decaying organic matter; in cool, wet springs they eat seeds and roots, making them a farm and garden pest. Meanwhile, the flies unwittingly alight on leaves with spores of a fungus that infects only flies. A spore attaches to their body and its rootlike hyphae penetrate the skin. Once inside its host, the fungus can affect fly behavior. In house flies, for example, females become hyper-attractive to mating males, thus ensuring they transfer the fungus to even more flies. In seed corn maggot flies, however, motion slows as the infection rages inside the fly, until the fly alights on a leaf and dies. Then the fungus erupts from its body and spews spores onto a new plant location. So while this fungus doesn't affect plants at all, be very glad it doesn't affect humans either!
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
Whorled or Stringy Stonecrop
This ground hugging sedum is a perennial succulent with a low, fast growth habit. A good choice for xeriscaping, it quickly spreads over a wide area. As a groundcover it likes to ramble along stepping stones, rock walls, and slopes or form a soft carpet beneath taller perennials. In containers it cascades beautifully. Its clusters of apple-green leaves are widely spaced along prostrate stems. Small star-shaped yellow flowers brighten the plant in late spring to early summer and attract pollinators and butterflies. This species is readily distinguished from other yellow-flowered sedum species by its whorled leaves. Best growth is achieved in average well drained soils in full sun to part shade. Once established it is drought tolerant. Occasional foot traffic is tolerated and recovers quickly. A shallow root system allows this vigorous sedum to be controlled easily by pulling and transplanting. As a bonus, it is deer- and rabbit-resistant. — Marian Hengemihle