The guava (Psidium guajava) originally hails from the Americas and thrives in USDA hardiness zones 9 through 11. The tree is relatively small, growing up to 20 feet tall, and produces a bounty of green and yellow fruit filled with sweet red flesh. Gardeners prize the fruit both for eating fresh and for juicing. Provide the guava tree with the proper watering, fertilizing and care it needs to encourage heavy fruit production and years of enjoyment.
Water the guava trees so the soil is moist to a depth of a couple of feet. Horticulturalists have yet to figure out the specific amount of water needed by the plant, according to the University of Florida. Generally, provide water every other day for the first seven days after planting a guava sapling. After a week, reduce this to twice a week for the next eight weeks. Thereafter, the university says guava trees can survive on rainfall supplemented with manual watering whenever it doesn't rain for five days.
Fertilize the guava trees to provide extra nutrients that encourage vigorous growth and fruit production. Start fertilizing in the spring when the plant starts growing, continuing to feed the plant once a month into the fall. Texas A&M University recommends using 21-0-0 fertilizer. Apply 1/2 cup every month during the guava's first year of growth, doubling the monthly amount every year.
Mulch around the guava tree. Mulch deters weed development and helps to conserve soil moisture, according to the University of Hawaii. The University of Florida recommends organic mulching material like straw, compost and wood chips, and suggests gardeners pile the mulch 6 inches thick. Keep an 8-inch-wide mulch-free zone around the guava's trunk to avoid rotting the tree.
Prune the guava tree as needed to clip off damaged or dead branches. Otherwise, pruning isn't needed and not recommended by Texas A&M University.
Manage pests. Guava trees are occasionally attacked by various insects like the guava whitefly (Metaleurodicus cardini) and the guava moth (Argyresthia eugeniella). The best treatment procedures vary by region. Consult your regional cooperative extension office for pest eradication strategies in your area.