I've had good results so far using 30-10-10 on the calamondin I bought this spring. It bloomed profusely in May and has set fruit. Would it help to switch to a tomatoe fertilizer (15-15-30) during fruit development? As a further refinement to the regimen, would it be better to use 15-30-15 during the blooming period?
Stick with the 30-10-10 for most of the year since these bloom so frequently enough during the growing year. For giving this plant a rest period later during the Winter I would go with a 0-10-10 that has between 6- 10% Calcium in the formulation. Jim
Hi, Jim. A pamphlet from the fertilizer manufacturer also suggested using 30-10-10 during the growing season. But then I remember reading in various books that phosphorus and potassium should be increased during flowering and fruit development respectively. Does that advice apply more to annuals and perennials than to trees and shrubs?
A lot depends on how often you want to fertilize a container grown plant. While a plant is in bloom we do want to cut back in the amount of Nitrogen and use more Phosphorous and Potassium but you are going to have blooms while you have fruit set. If you could time it right then apply 30-10-10 before you have fruit, then go with a 10-20-20 or even a 5-10-10 or a 5-20-20 or similar while you have fruit on the tree and are getting the next round of blossoms. It is rare but not unusual for a Calamondin to have 3 crops on the tree all at the same time. We were taught to apply the same fertilizer to Citrus. For container grown plants a 3-1-1 mix works well. If it were my tree I would cut down on the amount of Nitrogen when there is fruit on the tree and give the plant a rest from any Nitrogen for a few months when we cool off and when we have less sunlight to work with or when we cut back on artificial light. Jim
The plant had two crops on it before I pruned it back to one; it now has the beginnings of a new one. It's a prolific beast - a good sign I think. There aren't many leaves left on it even though it has a fair number of fruit. Now I'm wondering if I should go with a 20-20-20 to balance leaf and fruit growth. I'm beginning to think fertilization is somewhat of an art.
