Choosing a planting location:
Clumping bamboos will give fastest, densest growth in areas that get anywhere from full sun to at least a few hours of direct sun during the course of the day. The small to medium types are more shade tolerant than the giant types, and can do pretty well even if they get just a few patches of direct sun moving across them during the day.
Another factor to consider is that having evergreen tree canopy around offers considerable protection from winter cold. Depending on what species you are planting and how cold it gets in your area, it might be advantageous to compromise in choosing a site that gets shaded for a portion of the day in exchange for the protection of an evergreen canopy. See Cold Hardiness for more discussion of this.
Bamboos seem quite adaptable to soil type, doing well in either sand or clay soils as long as their nutrient and water needs are met. Even the lime rock rubble ‘soils’ of South Florida can grow fine bamboo groves. Clumping bamboos seem to be somewhat more tolerant than runners of flooding, and can generally handle at least a few days underwater without problem. Royal bamboo seems to be especially tolerant of flooding – I heard on report of a patch of Royal which had standing water around its base for six weeks, and was unscathed.
How to plant:
For best results, it is recommended to amend the soil with organic matter when planting. One good, cheap material is composted cow manure, readily available at retail garden supply centers in forty pound bags. Depending on your ambition level, allot anywhere from a half a bag to three bags per plant (more is better, but it is a lot of work and weight). Other sources of organic matter can work well, too, including homemade compost, and well-aged cow, sheep, or horse manure.
In making your planting hole, figure on digging a space approximately two to three times the diameter of the pot, and about one and a half times the depth of the pot (or root-ball, in the case of a field-dug plant). Start back-filling the hole with a fifty-fifty mix of the existing soil and your added compost, preferably with a hose running into the hole with enough water to turn the into soup as you back-fill. Take the plant out of its pot, and set it in the hole so that it will be slightly deeper in the ground than it was in the pot, and continue to back-fill with soil and compost. Finally, shape the last soil you replace into a donut-shaped ridge a couple of inches tall around the plant, so the plant is at the bottom of a little crater. This will help catch water and funnel it right to the roots.
The final step is to apply a thick layer of mulch around the plant. Clumping bamboos develop a network of very fine roots near the surface that benefit from the water retention effect and nutrient release from mulch. Almost any course organic matter will work, including wood chips, pine bark, raked up leaves, or pine needles. In many areas, tree-trimming companies working on contract for local utilities will dump a truckload of chips in your yard for free. It’s easy to skimp on the amount of mulch you apply, so try to make sure the layer is at least three inches deep for at least two feet in all directions from the plant. Mulch breaks down quickly in Florida’s warm, humid climate, so you’ll need to top off the mulch layer at least once a year. Also, make sure to remove any competing vegetation from the mulched layer.
After planting, the most important thing to do to insure rapid growth is regular watering. Make sure the plants get a good soaking once a week during the cool season, and three times a week during the warm months (especially during the summer, rains will do this job for you some weeks).
Fertilizing can also be helpful; a 10-10-10 granular type applied three to four times over the course of the warm months will help speed growth. Rake the mulch back and apply directly to the soil surface in a ring no more than a foot from the plant, then pull the much back. This will insure maximum absorption by the plant and minimal runoff (which can pollute waterways).
One more tip: Once you’re done planting your new bamboos, take pictures! In two or three years when your bamboos are getting big and beautiful, your friends won’t believe you when you tell them what scrawny little things they were when you planted them.
These planting and maintenance recommendations are for giving your plants optimal conditions for maximum growth, and are not a strict requirement if you don’t mind the plants having a slower growth rate. I have seen clumping bamboos set in the ground with no soil amendments and little care beyond an initial bucket or two of water dumped on them at planting. Some of these have done fairly well, especially those in soil that is naturally somewhat moister and richer. These have grown somewhat more slowly than under good care, but eventually became quite respectable plants. In other cases this super-low care approach has resulted in plants a decade old reaching no more than a quarter of their ultimate possible height.