Bamboo—Thumbs Up Or Thumbs Down?
No one waffles when you ask their opinion of bamboo in the garden. People either love like a mother or hate it like the devil. For some, it rescues them from a life of looking at the junk cars, broken pots, and caved-in toolshed next door. For others, it's a rapacious, irresistible invader bent on overrunning every inch of your property.
Bamboos, you may be surprised to know, are giant, woody grasses. Some form clumps and cause no problems. However, most are running, spreading rapidly underground by thick rhizomes—sometimes as thick as your forearm—torpedoing unseen through the soil. From the rhizomes grow canes, called culms. Giant bamboos are the fastest growing plants on Earth, even faster than kudzu. Some culms can grow four feet a day! Starting each spring, culms grow to their full height in about 60 days and grow no taller after that. Culms with small root systems may grow to 10 feet. Culms with large, established root systems may grow 70 feet tall. Individual culms live for about 10 years and then are replaced by new ones.
The ability to plant a nearly instant, evergreen screen that grows 30 feet tall or more in a short time is the primary reason people plant running bamboos. (Clumpers are shorter, less dense, and less effective screens.) But if you plant a running with no thought to control, the ground between your neighbor's house and yours could soon become a militarized zone.
How can you kill/control running bamboos? The knee-jerk solution is to grab a tank of Roundup or Brush Killer and douse those suckers! This won't work. Oh, you may kill the top growth, but that huge root system will sprout again next spring.
What you need to do to kill unwanted bamboo is to take advantage of the fact that new culms sprout only in spring. They look like the tips of asparagus spears. Wait until they're about a foot tall and either cut them off at the ground or push them over with your foot. It's easy. They will not grow again. If your neighbor has bamboo sprouting in his yard, make sure he does this too. Eventually, you'll starve the root system and the bamboo will die.
To control where bamboo is allowed to grow, dig a trench at least 24 inches deep around the bamboo bed. Line the trench with a physical barrier. High-density polyethylene of 60 mil or greater is the best barrier, because it won't rust like metal or crack like concrete. Install it with the smooth, shiny side facing the bamboo. For more info about different kinds of bamboo and bamboo control, go to lewisbamboo.com.