The Best of Bamboo
The conventional wisdom about bamboo is that once you've planted it, you'll soon be chasing it with a machete or hiring someone with a backhoe. But the truth is, there are two distinct categories of bamboo, and it makes a big difference which one you choose.
Here’s the scoop: running bamboos do exactly that — that is, run. They produce extremely tough underground stems called rhizomes. As the bamboo grows, the rhizomes snake farther and farther from the mother plant searching for water and nutrients, sending up additional canes as it goes. A running rhizome can spread indefinitely — only a heavy physical barrier and some ravenous pandas can slow their growth.
On the other hand, the politely clumping varieties have taken a bad rap for their over-zealous relatives. With compact rhizomes that stay put, these desirable bamboos don’t spread out of control or need containment.
The following bamboos have clumps that expand a few inches per year, like any other perennial, and fit most garden situations as to hardiness and habit:
Fargesia sp. The easiest of the bamboos to find and among the hardiest, members of this genus range in height from eight to 20 feet and many are hardy at -10 to -20 degrees F. Blue fountain bamboo (Fargesia nitida) grows to 12 feet and is hardy to -20 F. The leaves are delicate and slender, and the plant retains a vase shape. Named for its dark purple canes that are covered with a bloomy cast when young, this bamboo needs shade, and it doesn't stand up to heat. In warm areas of Zone 6 and 7, give it mostly shade, or better yet, use F. robusta and F. ruba, which have shown heat tolerance. For Zone 8 and warmer, consider Thamnocalamus tessellatus, which is hardy to about 5 degrees F, or Bambusa multiplex, which is hardy to 15 degrees F.
Borinda angustissima is a tight clumper that grows to some 18 feet tall, likes partial shade and is hardy to 15 degrees F. It has dainty, delicate leaves and in early summer the new canes exhibit remarkable purple-red cane sheaths.
Chusquea culeau. Cultivated in England for hundreds of years, this bamboo grows to 15 feet in height, tolerates sun or shade, and is hardy from 0 to 15 degrees, depending on the clone. The canes are a wonderful mixture of green and chartreuse, a striking combination. The plant is upright, but the tops of the canes cascade and gently weep. As the clump matures, the tops sport giant feathery plumes.
Keep in mind, if you are too timid to release clumpers in the garden you can watch them for a year or two before you plant by putting them in large containers. Remember that plastic containers can split in cold weather, and metal and cement containers aren't good insulators from the cold. The best containers for keeping a bamboo outdoors is a very large wooden whiskey barrel. The plant can stay in such a barrel for two or three years before needing division.
Taking a chance with runners
If you feel truly venturesome, try Pleioblastus fortunei, a runner that has variegated foliage. The spiky appearance makes it look more like an ornamental grass. It tops out at about four feet tall, and it's hardy to -10 degrees F. I have grown one of these outside in a protected location for more than seven years. In the spring to get this plant going, give it a good haircut. It can take sun or shade. Pleioblastus viridistraitus has chartreuse leaves striped with a handsome dark green. These will look cute and sweet in the pot, but don't forget to treat it just as you would a small lion: Don't let it out of its cage.
Bamboos are quite wonderful if we understand their growth habits and buy those that fit our needs.