Bamboo is grass that resembles a tree or shrub. The segmented trunks and long, sporadically placed leaf fronds give bamboo its memorable appearance. Bamboo comes in two varieties—clumping or runners. Clumping bamboo grows from a rhizome in a slowly expanding clump and is most common of the tropical varieties. Runners are usually temperate and the rhizomes spread outward. Runners pose the most problem with spreading, and need to be cut down to avoid taking over your yard and your neighbor's.
Cut through the rhizomes that connect the culms, or bamboo trunks, to your main grove. Use a spade to dig a shallow trench between the stray bamboo and the grove, severing the rhizomes, which lay near the soil surface, with your spade.
Cut off each culm at soil level using a sharp pair of pruners. Use a chainsaw for culms over 3 inches in diameter.
Water the cut-down area throughly and apply a general purpose fertilizer to encourage new growth from the rhizomes. This encourages the cut-off rhizomes to put forth new growth and exhaust themselves until they die off.
Cut off new shoots as they appear at soil level with pruning shears. Check twice a week for new shoots and remove immediately so the rhizomes don't get a chance to put out leaves and regenerate.
Continue removing new shoots as they appear for the entire growing season or three to six months in mild climates.
Dig up the entire rhizome mass to remove clumping bamboo completely. Remember that the entire grove is part of this rhizome and this will destroy all of it.
Cut off just the culms you want removed from the grove if just thinning or harvesting. Cut off culms less than 3 inches in diameter with pruning shears, removing at soil level.
Use a chainsaw to cut off culms more than 3 inches in diameter at soil level. Use caution not to cut into neighboring culms while trimming this way.
Remove culms from the outside of the clump first, then thin the center if necessary.
Water the remaining bamboo and fertilizer with a general purpose fertilizer after cutting back. This prevents shock to the rest of the clump.