Q: I use Jobe spikes to fertilize my fruit and nut trees. Last year I fertilized in mid-February and when I went to fertilize again at the end of May, I noticed the February spikes were not used up. I use drip irrigation and put the spikes near the emitters. How long do I need to wait between refertilizing with the spikes?
A:Β It depends. Fertilizers in a solid spike or granular form are going to dissolve as a result of exposure to water and warm temperatures. The manufacturer typically recommends applying them at the drip line of your trees so that rain falling off the tree or drip irrigation properly installed there will help dissolve the fertilizer. If we have a cooler spring or not much winter rain, itβs possible the spikes will last longer than advertised. Also, you probably donβt need to fertilize throughout the year. Mature trees donβt need much fertilizer and they are able to get many nutrients from the soil. A late winter application will likely suffice for the year.
Peter L. Warren is the Forest Health Program Coordinator for the Arizona Department of Forestry and Fire Management. Questions, photos and videos may be emailed toΒ tucsongardensage@gmail.com
