Care of Bamboo
As a general rule of thumb, the larger bamboos are planted in full sun. Most of the hardy mountain bambos and Sasas are happiest when protected from the hottest part of the day. Most variegated varieties are more brilliant when planted in partial shade. After choosing your site and preparing the soil, place plants and mulch well with grass clippings (for silica), partially decomposed wood chips, and straw (2 inches or more is recommended). Water your newly planted bamboo frequently in mild weather: usually twice a week will suffice. In hotter weather, watering every day may be necessary. Do not over-water! Yellowing of leaves may indicate over-watering. If leaves curl, this is an indication of either not enough water or too much leaf-to-rhizome ratio. If leaves curl during the day, but relax at night, remove some of the lower branches. Check your mulching to insure protective covering for rhizomes. If curling is constant, reduce size of plant by about 20%. Do so a little at a time. Stake larger bamboo in at least 3 directions. Some yellowing is most often present in spring, as bamboo changes its leaves out yearly.
Bamboo loves food and water but it doesn't like to soak in water. Make sure you have good drainage and proper mulching. Please leave bamboo leaves as a mulch: it is a good source of silica. Feed heavily in spring before start of new culm growth. We use lawn fertilizer with a 3-1-2 ratio ( 21-7-14 ) first in March, then again at the end of May. In the fall we use 5-10-10 or 0-10-10. Insuring a minimum of 1 inch of water a week during the growing season is optimum.
Control of bamboo is probably the most frequently asked question of us. We do not use vertical barriers any more. The effect of the sunken pot after a few years, besides providing a false sense of security, also generally resulting in a decline in plant health. With the barrier, you effectively stop all sub-irrigation of water; thus, the only water the bamboo gets is what falls directly on it. Just as there is a risk of salts from fertilizer building up in potted plants, the same is true with cooped-up bamboo. We use the method of rhizome pruning. In the Northwest by the first week of October the rhizomes that have spread will have stopped. Going around the perimeter of the planting with a spade, cutting straight down with overlapping cuts, severs the so far unviable rhizomes leaving them as worm food. In warmer areas, a second rhizome pruning may be necessary in November. Your bamboo will respond to care, but it will survive with neglect. Information is the key to success with bamboo. There is no reason to end up with a problem plant with proper planning and selection.