Q. Is there a recommended schedule for fertilizing fruit trees in the valley?  Also for citrus and grapevines?  The schedules I’ve read for each of these are differ depending upon who wrote the article and are not specific for the valley. Fertilizer applied around the source of water to the fruit tree, in this case a bubbler which will wash the fertilizer into the root zone A. It does not make that much difference as long as the plant has nutrients available during times of fruit production and fruit bud development but generally speaking we avoid applications which might encourage a flush of succulent growth just before winter sets in. This just means try not to apply fertilizers after about mid-July.             You can get by with a one-time fertilization in the early spring (January) for most fruit trees if you want to. The next thing you can do is a half application in the spring (January) and the other half after harvesting the fruit. Here fertilizer stakes are pounded into the soil close to the source of water going to the tree but not close to the tree itself             The third way is very light applications of fertilizer sprayed on the foliage or leaves of the trees, monthly, suspending applications from August – November as the tree sets up for winter dormancy. I usually use one of the granular fertilizers that dissolve totally in water such as Miracle Gro or your favorite organic liquid fertilizer. We fertilize just about all our fruit trees and vines once in January with a soil application and that’s it.