25 Year Old Grapefruit Tree With Crystals Coming From Trunk



Readers grapefruit tree trunk with crystals coming out

Q. My grapefruit tree is about 25 years old and has always produced an abundance of fruit.  A few months ago, I noticed a crystallized substance coming out of various spots on its lower trunk.  Also, some of the leaves had developed tiny black spots, had turned yellow and had fallen from the branches. I attached photos.

            I would appreciate any help you can give me about this and what to do to stop the flow and save the tree. There are about a dozen or so grapefruit on the tree now. Are they OK to eat?

A. I posted your photos on my blog for others to see. Probably my biggest concern for your tree is it getting enough water and applied at the right times and deep enough. Frequently this type of damage is associated more with stress than anything else.

Readers grapefruit tree with crystals coming from limb

            It is also possible that this could be the result of some cold/freezing damage from a previous cold winter. In other words, I do not believe it is due to insects or an active disease. It is possible it is due to some “disease” caused from environmental stress. This type of damage can revert to an active disease problem if you do not keep the tree healthy.

            So my recommendation is to not put down any chemicals for insects or disease but to concentrate on plant health by fertilizing in the spring with a citrus fertilizer. This would be done around or prior to flowering.

            Put the fertilizer near the drip emitters or source of water so the fertilizer is pushed into the rootzone of the plant. You might want to take a look at tree fertilizer stakes but keep them at least a couple of feet from the trunk. If the source or water for irrigation is close to the trunk, move it away the same distance. 

            It is okay to start with two drip emitters for new trees but in a few years you should be adding more emitters which will allow you to spread the water more evenly under the trunk and add more water at the same time which it needs as it gets bigger. Bigger trees need more water than smaller trees regardless of the type of tree it is.

            This spring water the area under the canopy deeply and thoroughly. Add an iron chelate fertilizer when you are adding your other fertilizer as either granular, liquid or tree stakes. Like any fertilizer, it needs water to move these fertilizer salts into the rootzone.

            Prune out any dead or dying branches, crossed branches, branches growing straight up or straight down. These are unproductive and just shade the interior of the tree.

            The fruit is fine to eat as long as you have not applied any pesticides recently.