Bamboos are ornamental grasses that grow from rhizomes. In nature, bamboo grows under a protective canopy of taller forest trees that both protect it from excessive sun and provide fertilization in the form of dead or dying leaves, and bird or animal droppings. In many cases, bamboos growing in your landscape may benefit from added fertilization.
Types of Fertilizer
You can use either organic or chemical fertilizers with your bamboo. However, if using chemical fertilizers, follow the instructions on the package carefully to avoid overfertilization. Organic fertilizers, on the other hand, are gentler and there is less of a risk of overfertilization.
Amount of Fertilizer
Bamboos are heavy feeders. Different types of fertilizer have different fertilization techniques and schedules. Fertilizer packaging offers a range quantity or frequency, and sometimes both. Fertilize at the high end of that suggested range. If your bamboo is growing in a place where it leaves from nearby trees fall on the ground, you may not need to fertilize as much.
As a member of the grass family, bamboo responds well to higher nitrogen fertilizers. Use a balanced chemical fertilizer that has moderate amounts of nitrogen, phosphorous and potassium (N-P-K), such as a 30-10-10 or a 28-14-14 or a balanced organic fertilizer that favors nitrogen content over phosphorous and potassium. Those both will provide good balance, with the boost of nitrogen that helps keep bamboo green.
Most water-soluble, balanced chemical fertilizers will work well with bamboo. Slow-release fertilizers may reduce the required frequency of fertilization, and thus may reduce the amount of work required to grow bamboo. When using chemical fertilizers, be careful not to overfertilize the plant as it can cause damage to the roots and eventually result in the death of the bamboo.
Organic fertilizers can be good for bamboo. Organic fertilizers have lower percentages of nutrients than chemical fertilizers. As such, they may need to be applied in larger quantities and more often. Balanced fertilizers that are higher in nitrogen include cottonseed meal, soybean meal, bat guano and fish emulsion. Organic fertilizers are gentler, making it harder to over fertilize your bamboo.
Bamboo uses soil silica to create the hard outer layer of its canes, according to Terra Viridis Nursery. However, it hasn't been shown that adding silica is effective as fertilization. It's better to use a water-soluble form of silica if you plan to add supplemental silica to your bamboo.