Guava trees are shallow-rooted, fruiting evergreens that can be easily toppled by strong sustained winds. Although some varieties can reach 33 feet tall, it's usually best to keep them under 12 feet to avoid extensive wind damage. Pruning guava trees is a relatively simple procedure.
Cut very young, newly planted guava trees to 1 to 2 feet tall if they lack lateral branches. The plant will respond by producing new shoots that will grow into branches, eventually creating a full canopy.
Remove suckers from the guava tree's base and trunk as they appear.
Choose three to four strong lateral stems to retain as the young tree's framework when new shoots are about 18 inches long. They should be evenly positioned on the plant in a way that appeals to you. Remove all other stems during the winter.
Nip 1 to 3 inches from the tips of the framework limbs when they're 24 to 36 inches long. This will promote further branching. When the shoots on the ends of these limbs grow to 24 to 36 inches long, tip them to induce further branching and fullness.
Remove any shoots on the framework limbs that are growing straight downward, and continue to trim off suckers as they appear.
Prune out the oldest limbs from the center of the tree any time during the year after the tree reaches fruit-bearing age, typically 2 to 4 years old. Remove any dead, damaged or diseased limbs. If the center of the plant is extremely dense with smaller limbs and foliage, cut some of it out. This will allow sunlight and air circulation throughout the canopy.
Nip the ends as needed to keep the plant tidy and shapely, but remember that new growth is what produces fruit the following year.
Cut back the entire tree during the winter by as much as 1/3 if it is overgrown, or if it's becoming too large for your taste.
Prune every two to four years as needed. An indicator that pruning is needed is a reduction in fruit production.