Fertilizing trees is a great way to keep trees healthy and is especially important for revitalizing sick trees. I highly recommend you read my four part series on tree fertilizers. You can access them by clicking on the fertilize link under categories on the right sidebar. This article is aimed at pointing you toward a few fertilizer products you can buy to do the job yourself. Some of the tips here will help you with the timing of the right application, but you do need to read the label of the product you are using to make sure you are applying it at the right rate.
The first product I want to point you toward are tree fertilizer spikes. These citrus and fruit tree fertilizer spikes will get the job done. The only difference between the fruit tree spikes and the normal tree spikes is that the fruit tree spikes have some sulphur and micro nutrients mixed in. These are better for all trees, not just fruit varieties. These spikes are the only “conventional” fertilizer I am going to recommend to you; everything else is more like a supplement. They should be put in the ground in the fall. Sometime around late September or October.
Mycorrhizae (my-kore-rize-ay) should also be applied in the fall. Here is a product I found that you can order from the internet. To get the best benefit, break up your application into a few treatments. Put half your annual application down in the fall; do a quarter of it in March and the last quarter in late June or July. Mycorrhizae is a fungus that grows on the roots of the trees and then makes a rootlike system of its own. The fungi then shares what it absorbs with the tree. It’s a good way to improve water and nutrient uptake and a good way to combat summer drought stress. Mycorrhizae application will be mixed with water and sprayed to drench the soil.
Both of the next two products should be mixed together when you apply them: humic acid and superthrive. Humic acid is one of those products that we know helps with nutrient uptake, helps clean the soil and we think it has a good effect of growth hormone balancing. The truth is no one really knows exactly the science going there. But, I can tell you from experience it really works great! I’d consider this to probably be the most important product you use. Superthrive is a hodge-podge of all kinds of different things we know are good for plants. The ingredients range from micronutrients, growth hormones, vitamins, enzymes and countless more good stuff. Apply your mixture of humic acid and superthrive to the soil under the dripline of your trees every 6-8 weeks.
To spray down your treatments I recommend this product. You can attach it to your water hose and it will mix it with water on the fly. This makes the application a breeze.