Thamnocalamus crassinodus – Clumping Bamboo for Shade
I have been holding off on this article, in hopes that my Thamnocalamus crassinodus would re-foliate after the hard winter we had here, but a few new shoots are emerging now (picture right) and still no signs of recovery. Temperatures here at the nursery dropped to about 13 degrees F. a couple of times last winter, but we had several weeks that day time temps barely rose above freezing that hurt this plant the most. Click on a pic to view a larger image. In previous years, T. crassinodus suffered some winter damage, but always recovered quickly, filling out with wonderful new foliage by late spring. However, the extended cold and low temperatures of last winter appear to have been too much for it. I am going to try it in a more protected location, but at this point, it looks like you can expect complete dieback (picture right) during the coldest winters, about every 10 years or so in the colder microclimates of Western Washington. Culms One of the outstanding features of this bamboo is the cane color. If exposed to some early morning sun, canes and branch ramifications turn red-purple, (picture right) deepening in color over the growing season, eventually fading as newer stems emerge and enter the color cycle. T. crassinodus is a clumping bamboo that has a vase shape form, and under ideal conditions, reaches up to 20' high. The culms have a slightly open habit and it grows fairly quickly, so it will take up a good chunk of garden real estate once established - expect about a 6' spread from a tall #5 container in 5-6 years. Foliage The leaves are narrow, medium-small, delicate and more sparse than other bamboos (picture right). Combined with the relatively open culm spacing of this bamboo, the result is a very graceful, airy, and somewhat transparent effect in the landscape. Growing it Well This bamboo is one of the very few that will thrive in full shade. For best growth, a few hours of early morning sun at most, or full shade along with rich moist, soil make it very happy. This bamboo is a good "coastal" candidate because it isn't very heat hardy, or cold hardy, as I found out last winter. Fortunately, the deeply shaded areas that this bamboo will thrive in are also likely to be protected from wind and to some extent, extreme cold. So, if you are looking for a substantial plant to grow in that deeply shaded area of your garden, this bamboo is worth giving a try.