Bamboo Good and Bad

Bamboo comes in two basic forms, clump and common. Unless you are prepared to build barriers to restrict the spread of common bamboo, use only clump bamboo for landscaping.
    Unlike the common bamboo that propagates itself by producing rhizomes underground, clump bamboo produces very tight-growing clumps and can only be propagated by divisions. Some of the clumping bamboos enlarge by only a few inches a year, while some of the more vigorous forms of clumping bamboos will enlarge by eight to 10 feet each year.
    The size of clump species can be easily controlled by root pruning. Many of these clumping bamboos are very attractive with black to purple stems and intense green leaves. Some clumping bamboos grow only a few feet tall, while others may grow up to eight feet tall. The Kert Blumel Nursery in Baltimore County is probably the largest producer of clump bamboos.
    Planting common bamboo, on the other hand, is a mistake you will live to regret. Common bamboo is attractive because it forms a dense screen quickly and remains green most of the year. The problem is that these plants produce rhizomes that can soon take over the yard, even a neighborhood.
    Common bamboo rhizomes travel underground a yard or more in a year and penetrate sandy soils as deep as two feet. The rhizome tips are pointed and capable of penetrating industrial plastic films and have been known to travel under 12-foot-wide concrete driveways and sprout through asphalt surfaces.
    Bamboo rhizomes can be contained by trenching the perimeter of the area to a depth of three feet and lining the trenches with either fiberglass or bolted together aluminum paneling with roofing asphalt sealing the joints. The paneling must protrude above ground at least 6 inches so that the rhizomes, should they grow to the surface, will not survive.
    In my opinion, the common forms of bamboo should be banned because they are invasive and create more problems than they solve.
    Next week: How to kill it.

The Bay Gardener On Call

   I was greeting subscribers to the season’s last concert of the South County Concert Association at Southern High School in Harwood when a man presented me with a small plastic bag containing a weed from his lawn and asked how to control it.
    The weed was wild violet, and the most effective means of control is spot spraying with a chemical known as Tri-Mec at the recommended rate of application. For good control, he needed to spray the area twice, making the second application in seven to 10 days.
    Since I serve as master of ceremonies for the concerts, I asked the audience how many read Bay Weekly. Approximately 20 percent of the audience of 900 raised their hands.
    I then asked how many recognized me as the Bay Gardener. I was surprised to see a large show of hands.
    At intermission and after the performance, a number of people came to me with their own weed problems as well as other garden questions. Now that the cat is out of the bag, I anticipate conducting plant clinics at future performances.

Ask Dr. Gouin your questions at [email protected] All questions will appear in Bay Weekly. Please include your name and address.