How to Make a Calamansi Tree Give Fruit

Although it resembles the lime, calamansi is the result of a cross between the mandarin and the kumquat. One of the most important factors to consider when making a calamansi tree give fruit is the region in which it is being grown. It requires lots of sunshine and little rain, within Zones 9 and above on the U.S. Department of Agriculture Hardiness Zone Map. If you have a young calamansi tree, keep in mind that it won't bear fruit until it is at least two years old.

Step 1

Take soil samples from around the calamansi tree and have them tested for pH levels. The calamansi tree requires a soil pH between 5.5 and 6.5 to flower and set fruit.

Step 2

Raise the pH by adding agricultural lime, at the rate suggested by the soil test results and carefully water it into the soil. Don't apply more than one-half inch of water. Lowering the pH of alkaline soils is quite challenging and may be impossible. Consult with the county cooperative extension office in your area for assistance.

Step 3

Fertilize the first year calamansi with 2/3 cup of each of urea and 16-20-0 fertilizers, mixed, in spring and again every four months thereafter. When the tree reaches two years of age, and each year thereafter until it is eight, give it three pounds of 12-24-12 fertilizer two months after it flowers and then again immediately after harvest. When the calamansi tree reaches eight years old, supply it with four to six pounds of 12-24-12, according to the same schedule.