Bamboo: the easy exotic

Flower & Garden Magazine, Feb-March, 1996 by Rick Cook

CARE & FEEDING

Simply treat bamboo like a grass and it will thrive. Bamboos like the same sort of high-nitrogen fertilizer used on lawns. Likewise, bamboo can be damaged by the same weed killers that eliminate grass.

Big plants like bamboo need a lot of food and water to encourage maximum growth. I tend to feed and water heavily in the first season, even for plants whose size I want to control, in order to establish the root system.

Most bamboo species are fairly drought-tolerant once established but they do best with ample water, especially during their growing seasons. If the plant's leaves remain green through the winter it will need some water then as well.

Ideally bamboos like soil that is moist but not saturated. Overwatering causes the new culms to rot at the base and will eventually kill the plant. Better to err on the dry side until you find the plant's natural rhythm. When bamboo is stressed for water, the leaves tend to roll up like tubes. It is best not to let your plants reach that stage but it won't harm the plant if it happens occasionally.

I like to side-dress my plants with compost once a year and feed them three to six times a year, depending on the species and the weather. If I'm trying to encourage a fast-growing species, I may feed it every other month in the spring and summer.

The rule for cultivating around bamboo is equally simple: don't. Despite their size, bamboos are very shallow-rooted, and even the largest species will have most of their roots in the top foot or so of soil.

When I set out a new plant, I mulch around it with pine bark, then leave the fallen bamboo leaves under the stalks as a natural mulch. After a year or two it's very unusual to have weed problems in a stand of bamboo. Of course, you won't have much luck growing groundcovers or other plants in your bamboo grove, either.

THINNING AND HARVESTING

One thing about growing bamboo: you never have a shortage of plant stakes. If you want your stand of medium-to-large bamboo to thrive, you will have to do some thinning anyway. Bamboo culms reach their peak as timber after the second growing season, and the culms of most species lose vigor and start to die after three or four years. Thinning removes the worn-out culms and lets light into the center of the clump to encourage new culms.

The best method of thinning is to select culms at least two years old and harvest them by cutting them close to the ground with a pruning saw. Open up the stand to encourage new culms all through the clump rather than just around the periphery. Then trim the branches off the harvested culms and and set the culms aside to dry into poles. If you want to use the bamboo in craft projects or as building material, keep in mind that it is much easier to work green; do any shaping or bending before it dries.

While mature stands often branch for just the top one-third of the culm, younger plants tend to have branches right down to the ground, giving your bamboo a shrubby look. For appearance's sake you may want to trim off the lower branches; the easiest way is to cut out the bud at each node as it begins to swell. Doing so will give you smooth bamboo poles without branch stubs. Use a sharp knife to remove the bud callus as it begins to thicken. Another option is to clip off the branches with pruning shears. If you use the poles as supports for beans or other climbing plants, the branch stubs offer a hold for the tendrils.