Bamboo is actually a giant grass. It is much loved, but can have a frightening growth rate. The best way to to avoid this nightmare is to choose a species suited for your landscape situation. Bamboos also love wet areas, which can greatly accelerate their growth rate. Never place any form of bamboo near natural waterways. With these considerations, bamboos can evoke a peaceful elegance to the garden environment when well managed.
The most popular running bamboos are the timber bamboos. They spread by developing underground runners that can appear 100 feet from the original plant. Since bamboos flower only every 100 years or more, this is their way of reproducing and developing new colonies. Bamboo barriers are helpful, providing they are deep and sturdy. Keep in mind that the runners climb over the barrier, so twice yearly trimming is recommended. Large containers work, but the culms can break through over time. Remove the bamboo occasionally, and trim away some of the canes and roots, then repot the bamboo. Two popular species of timber bamboo are golden bamboo (Phyllostachys aurea) and black bamboo (Phyllostachys nigra). Both reach up to 35 feet in height.
Clumping bamboos also grow at a healthy rate. The difference is that the clump expands without producing runners. Control clumping bamboo by trimming away some of the canes, or separate them by root divisions. Clumping bamboos are less of an environmental concern. A popular group of clumping bamboos is the Fargesia. This type has a feathery appearance and blue-green foliage. It does not develop the large canes that timber bamboos do. But it provides a good way to have the look of bamboo, without the invasive qualities. The blue fountain bamboo (Fargesia nitida) is a popular species of clumping bamboo. Another hardy blue bamboo is the umbrella bamboo (Fargesia murielae). Both of these species reach between 12 and 15 feet tall, and are hardy to USDA zone 5. A slightly more tender species, Fargesia robusta, develops white sheaths, giving the plant a striped appearance. This one reaches about 10 feet tall, and is hardy to USDA zone 7.
Ground-cover bamboos are running bamboos, and can be aggressive. Still, the plants are smaller, making them easier to manage. It is still important to grow them in areas where they have room to expand. A good application is under trees, where filtered sunlight can come through. Cut away runners that want to escape the given area. Ground-cover bamboos reach 2 to 5 feet tall. They can be kept sheared to as low as 1 to 2 feet tall. The most popular hardy species is Sasa veitchii. There are green forms and variegated forms that are very ornamental. They are hardy to USDA zone 6. An even tougher ground-cover bamboo is Sasa hayatae. This one is 3 feet tall, and is hardy to USDA zone 5. It has shorter, narrower blades than Sasa veitchii. Pygmy bamboo (Pleioblastus pygmaeus) is another hardy dwarf bamboo. It reaches 2 feet tall, and is hardy to USDA zone 6.