From 30′ tall growing timber bamboo to the ground cover pygmy bamboo there is a bamboo for every garden. There are dwarf varieties that are great for screening on patios to tall varieties great for screening out tall buildings, all of which are quite easy to grow.
Bamboo grows and spreads by rhizomes, which are shallow underground branching stems/roots. Fall is the most active season for rhizome development. The majority of bamboo species inhabit the top 6” to 12” of soil. Bamboo has been categorized into two broad regenerative categories. There are ‘Running’ bamboos, that are generally temperate (hardy) and spread exuberantly, and the ‘Clumping’ bamboos, which are usually tropical (tender) and slowly expand from the original planting.
Clumping Bamboos usually grow less than 15 feet tall because of their small, delicate culms. They usually grow as wide as they do tall. The vast majority of clumpers prefer shade from the hot afternoon sun. Most clumping bamboo are tender, meaning they cannot withstand our winters unless they are protected from frost by bringing them into frost‐free areas like greenhouses or heated garages. Adding a good layer of mulch to them in the fall will help them through the winter, but in harder winters they will die back to the rhizome crown, with new shoots sprouting in the spring.
Running bamboo is the least understood and most unjustly feared of the bamboos. They generally have the look that most people want from their bamboos, they grow to their mature size quickly, and are very hardy. With their highly ornamental culms and leaves, running bamboos tend to be the bamboo of choice for hedging or screening. With proper containment and regular maintenance, running bamboos will be a joy rather than a bane.
We recommend annual root pruning as the first option for control. If you feel you must use barriers, use them only on running bamboo, and use them only along your property line or other places of major concern. Barriers often fail because bamboo will burst through them or grow over their tops. The only effective control of bamboo is maintenance and vigilance. Give your bamboo plenty of space for its growth and your maintenance.
If necessary, a barrier of 60 mil by 30 inch deep HDPE (high density polyethylene) can be used for rhizome control. If you plan to install a barrier to control the spread of running bamboos, it is important to install it properly to ensure its effectiveness. In other than very light soils, the bamboo rhizomes are usually in the top few inches of soil. However when the rhizome encounters an obstruction it will turn and sometimes travel downwards. It is important to avoid loose soil or air pockets next to the barrier or the bamboo may go deeper than you want and perhaps go under the barrier. When filling the hole after placing the barrier, tightly compact the soil next to the barrier. Any soil amendments must be added only in the top foot or so. You mustn’t encourage deep rhizome growth if you want to contain the bamboo. If a shallow trench can surround the bamboo planting 8 to 10 inches deep, this can be a cheaper and easier method to control its spread. You just need to check a couple of times in the late summer and fall to see if any rhizomes have tried to cross the trench, and cut them off. Checking for spreading rhizomes is very important. It must be done each fall, whether you are using barrier or a trench. Take time during the year, generally in the winter, to thin out your bamboo. In addition, harvest or eliminate all shoots except those that are coming up exactly where you want them to.
You will want to keep your bamboo cleaned out to keep it attractive and you may want to shape it so that it does not interfere with your activities. Hedges are simple, as you need to prune any bamboo culm only once: once trimmed, bamboo culms grow neither in height nor width. You will need to cut the new growth each year, but again, that is also only once. Bamboo is thus much easier to deal with than other evergreens, which grow constantly taller and thicker. Hand tools work well with bamboo. When you trim a bamboo, cut just above and as close to the node or branch as possible. This eliminates dieback. When you cut down culms you should cut them at ground level to avoid stumps, which are unsightly, dangerous, and rot slowly. Shoots should be harvested in the spring. Only allow shoots to grow where you want them to grow; cut down all others. Bamboos always send up extra shoots, and if all are unrestricted many will abort anyhow. The proper spacing for a bamboo forest is traditionally about 3 feet between culms, enough to walk between with an umbrella. Another method is to cut out all growth older than 2 or 3 years. Any time you have dead, broken, leaning, or crowded culms you should remove them. Harvested culms can be stored either vertically, or piled up horizontally.
For dwarf bamboo we recommend cutting it to the ground each spring, so that the plant is rejuvenated. It will look much nicer when the new growth emerges, and it will be kept shorter and denser. Dwarf bamboos are also often trimmed later in the season to keep them shorter and more uniform in height. In very cold climates such as Zone 4 or 5 dwarf bamboos may have their tops freeze back in the winter and still be good for landscaping. Just mow them as you should do in places where they don’t freeze back.
To protect your Bamboo through winter in harsh environments it’s a good idea to place mulch around it. About 4 ‐ 6 inches of pines needles, grass clippings, leaf debris or compost provides excellent protection to the root zone during hard freezes and dry winter conditions. For extreme conditions such as growing a bamboo not hardy enough for your climate, place stakes around the perimeter of your bamboo, place wire mesh around the stakes, and fill the area up with mulch (the deeper the better). If your bamboo dies to the ground due to an extremely cold winter, don’t give up on it, in many cases it will recover and regenerate in the spring.
In all its varied forms, the uses for bamboo are endless: striking, stand‐alone specimen plants, a low variegated border, groundcover, accent plants in pots on a deck or patio, an interesting entryway, or an Oriental look for Asian‐inspired garden. By far the most popular use of bamboo, however, is as fast‐growing privacy screens and evergreen hedges. Since bamboo is one of the fastest growing plants on the planet, bamboo screens and hedges can be created more quickly and inexpensively compared to other plants or trees. Running bamboos fill in the spaces between the original plants the fastest, and even with 3’ spacing some screening can be achieved within 2‐3 years with smaller sized pots. Clumping bamboos take more time to fill in, but are ultimately extremely dense. Almost any species can be used for effective screening, given that it will grow to the height you desire in the space that you can allow for it, and given that it is properly matched to your climate and planting area for cold hardiness and sun/shade.