The idea of growing bamboo sparks intrigue and fear in gardeners. We've all heard about bamboo running amok, making the term 'invasive' seem tame. But we've also seen a lot of garden magazines exhibiting gorgeous golden, striped and even black rustling graceful, plants, we know, would look wonderful in our own gardens. Is it worth the risk?
There is a very real chance that bamboo planted in your garden could become uncontrollable. Non-native plants can behave erratically, depending on the climate, conditions and care they receive. But there are more and more reputable bamboo dealers who are marketing clumping varieties of bamboo, targeted for growing in various areas. For the most part you still have to mail order bamboo plants, since the bamboo sold most commonly in nurseries is the most easily propagated type - aka, invasive. Here's a breakdown of what you need to know.
Bamboo is a grass (subfamily Bambusoideae within the family Gramineae). It can range in size from a few inches to over 100 feet - and can grow a foot or more a day. Bamboo is one of the most useful plants grown in the world. It's used as food, building material, animal fodder, ornamentation and screening. They are recognizable by their nodes, the joints between the hollow segments of the branch or culm, as shown in the photo.
What is Bamboo?
The easiest way to classify bamboo is to divide it into runners and clumpers. Botanical names can vary from region to region as much as common names, making it very confusing to try and sort out what type you have. (Err on the side of caution when planting any bamboo and always install some type of in-ground barrier immediately, at planting time.
Clumpers or sympodial bamboos will expand, just like any other perennial plant. However clumping bamboos have a limited root structure and cannot creep more than a few inches per year. They will expand a little each year and won't grow to mature height unless they are allowed to reach their desired circumference. Most of the clumping bamboos are tropical plants, but some of the Fargensia genus exhibit enough cold hardiness to survive done to USDA Hardiness Zone 4.
This is what makes gardeners run for cover. Running or monopodial bamboos spread by underground rhizomes and can cover great distances quickly. Since they are all connected as one plant, it becomes impossible to kill without getting every last piece of rhizome. However the rhizomes grow at a depth of only 2 - 18 inches and can be contained with 2 - 2 1/2' plastic edging buried around the circumference of the plant. Use a good edge. Any cracks or seams in the edging will allow rhizomes to get through. Most of the temperate, cold hardy bamboos are runners. [Temperate bamboos are used to a period of cold weather dormancy and may suffer leaf drop if you try to grow them indoors.]
Growing Bamboo: Some Key Points
- Most bamboos prefer full sun and a soil pH of around 6.0 - 6.2.
- Newly planted bamboo requires liberal watering.
- Lack of water is the biggest problem with growing bamboo.
- Bamboos require water to send out new culms.
- Standing water inhibits the growth of bamboo.
- Bamboo doesn't like competition from weeds.
- Taller bamboo should be staked, to prevent uprooting.
- Bamboos are evergreen and will lose and replace leaves as they grow.
- Since bamboos are grasses and are grown for their foliage feed with a high nitrogen fertilizer.
- Mulching will help control moisture and will protect cold hardy varieties in winter.
Bamboo culms do not live forever and some pruning should be done annually to remove old or damaged culms. Pruning does not hurt the plant. Cut back to just above a node, to avoid a stub.
Bamboo Mite: Similar to spider mites, in that it sucks the juices from leaves, but the bamboo mite only creates webbing within the yellow striation along the parallel veins of the bamboo leaf. Yellow streaking will slowly expand and spread.
Problems with Bamboo
New bamboo plants should be thoroughly inspected before being planted in the garden or near other bamboos. If an infestation occurs, insecticidal soap will offer some control, but it is hard to reach the mites under their webs. The use of a systemic miticide may be necessary.
Mealybugs: Mealybugs are part of the scale group of insects. They attach themselves to plants, often at hard to reach joint and often protect themselves with a cottony or shell like covering. This makes them hard to kill with a contact insecticide. The Bamboo Society of America recommends the use of Cygon (dimethoate), if necessary.
Still interested? Here are some selected bamboo varieties to try in your garden.