Dwarf grapefruit tree overpruned

Question from Chuck:
I made the mistake of pruning my dwarf grapefruit tree 3 years ago. I haven’t had a grapefruit since. What can I do? The tree is beautiful and healthy looking, but no fruit.

Answer from Pat:
If you cut your grapefruit tree back very hard, it might take several years for the tree to replace fruiting wood. Additionally you may have stimulated the tree to put all its energy into new growth and none into flowers and fruit. If so it will take a few years for the tree to get into balance again. If you cut back into hard wood your tree may even be subject to die-back. I have seen that happen with old lemon trees when someone has cut them back too far and made the cuts in the middle of branches, leaving stubs so those branches were unable to continue growing. Old wood can’t sprout new growth.

This does not sound as if it is the problem since you say your tree is beautiful and healthy looking. Your tree probably simply over-compensated with new growth.

But even if all this is true, yes I can help you. The best way for you to get your tree bearing again is in several steps:

1. Never spray your tree with pesticides especially Malathion. Malathion kills honeybees. Without bees you will have no fruit. (Blossoms will just fall off.) Sometimes gardeners are using other pesticides that kill bees or they are hiring a pest-control company that is using products that harm bees. Some lawn-care companies and commercial gardeners use lawn fertilizers that contain a grub control called Merit and this chemical kills bees.

2. Make sure there are honey bees in your garden. (If your tree flowers every year but does not have fruit, it could be that honeybees have disappeared and this is the real source of the problem.) Read the entries on Pollination on this blog for ideas how to attract honey bees. You can use ribbons made for that purpose or you can even purchase a pheromone for attracting bees. Create an environment that attracts and is friendly to bees by providing pollen-bearing flowers and a water source for bees such as a bird bath under your tree. If there are no bees but you have flowers on your grapefruit tree, hand pollinate them.

3. Is your tree growing in a lawn? If so, it may be getting the lawn fertilizer and it might be stimulating more growth than flowers and fruit.

4. If not in a lawn, next year fertilize your tree with a balanced organic fertilizer. Spread the fertilizer all over the root zone of the tree beginning two feet from the trunk of the tree and extending two or three feet out from the tips of the branches. (Roots of citrus tend to spread far.) A mature citrus tree can use the equal of one pound of actual nitrogen per year, but yours is a dwarf so take into account its size.

5. The most most important fertilizers to give your tree to get it bearing again are the bloom ingredients. Make sure you kick-start bloom again by including adequate phosphorus and potassium to stimulate bloom. If you are not an organic gardener, purchase a bottle of 0-10-10. Mix according to package directions and soak the root zone with it three times in late January and early February. Zap the tree three times like this with bloom ingredients (phosphorus and potassium) and your tree should resume blooming. There is an organic liquid bloom fertilizer also available at Hydroponic stores and on the Internet. I mentioned more than one product for this purpose in my book on the subjects of epiphyllum cacti and cymbidiums and maybe also cinerarias. I can promise you that if you zap your tree with liquid phosphorus and potassium in late January and early February and if you also have bees you can get it blooming again.

Blossoming of citrus is a February event, so from then on you can fertilize with a normal balanced organic fertilizer for citrus in January. It is fine to fertilize earlier in January with organics than one normally would with synthetic fertilizers because organic fertilizers take longer to work. Anyway, don’t stint on the organics but don’t over-feed either. (Purchase a bagged commercial organic citrus fertilizer and use that if you want or mix your own. See my book for ideas. Read the pages on fertilizing and caring for citrus in the January chapter.)

And from now on remember that in general citrus trees need little pruning. Hard pruning can damage and set back any fruit tree for several years thereafter. Good care, however, can help an over-pruned tree recover.