Fertilizing Citrus

Ten citrus trees (shrubs- really) grow on my property in San Diego. They are heavy feeders, from what I have read, and are often deficient in zinc and magnesium. Organic fertilizers are expensive, and now, with gmo, I do not want bird products or alfalfa in my fertilizer. I have a local source for free horse manure- if that helps. The trees are mulched with pecan leaves. Do you have any advice for me on how to fertilze my trees or how to take good care of them? If you know about citrus, can you give me a rough idea of how often and when to fertilize. A couple of them have lost most of their leaves and are looking poor, and I am not sure what I did wrong.

How often do you water them, and how much water do you give them?

I water every ten days or so. I check the soil and if it is moist i do not water. When i do water I water deeply. I have not watered this winter at all. They have also gotten increasingly shaded by some pines nearby. This may have something to do with their ill health.

Sharon Reeve wrote:I water every ten days or so. I check the soil and if it is moist i do not water. When i do water I water deeply. I have not watered this winter at all. They have also gotten increasingly shaded by some pines nearby. This may have something to do with their ill health.

I had problems with my citrus, and looked on the web, and requested advice and ended up with no satisfaction. The pages I found which described the symptoms were vague, and if I did try what they say, it didn't seem to make a difference. The advice I was given was never "I've had that exact problem, and this is what it solved for me", instead it was "Your problem is this, and this will solve it" and it never did.

Good luck!

I would try a light mulch, an inch or two deep of the horse manure and see what happens. If you mix it up with the existing pecan leaves and rake all into the surface soil a bit, you can't burn them. See how they do as spring comes on. If there's a bit of improvement but not much, give them some more.
It's also conceivable that there is something present (as opposed to absent) in the soil that is harming them. Salt, for instance, is a frequent problem in CA. A soil test might be in order if the trees are large and valuable.
In addition, are you certain the problem is from the soil at all? How long have you owned the property where the trees are, and have they always been in the condition they are now? Perhaps a previous owner let them dry out or otherwise abused them..... Have you checked for insects and diseases.....sublte things like scale can be hard to see and yet cause plenty of damage.....

Hi Sharon. Yes shade on your citrus trees is part of your problem. If you can get other items to add to your current mulching, I would layer them so there is a more balanced set of nutrients in the mulch. Horse manure in thin layers within the newly layered mulch will be a good thing. In your area, check for white flies, scale, and other nasty critters that love citrus trees.