Tree Fertilization

WHEN TO FERTILIZE A TREE?

The best time to fertilize a tree is in spring with the next best time being late fall. Trees are actively absorbing nutrients and moving sap through their trunk during the spring. The tree will perform better if the nutrition it needs is in the soil. We do recommend a soil test so you will know what your soil is lacking. Be sure to mark down the type of tree before sending your test off so you can get proper recommendations on what should be added to benefit your tree to most.

how often to fertilize a tree ?

Smaller and younger trees can be fertilized every year. Normally older large trees only need to be fertilized every two years. They typically do not need to be fertilized more than that unless they show signs of damage. Damage would usually be caused by insects, fungus or a severe drought in previous years.  If you are currently in a drought, please do not try to fertilize your tree back to health. If the tree needs water, fertilizer will actually cause your tree to get worse. Think about what would happen to a human who was severely dehydrated and ate to cure their dehydration.

HOW TO FERTILIZE A TREE?

First we need to discuss where the fertilizer is going to go. This may seem like common sense, but this is an area where most people mess up. On a large tree, the area from two to three feet from the trunk of the tree to one to two feet past the drip line is the place you want to apply fertilizer. On a small to medium tree, stick to the whole area from two inches from the trunk to the drip line. The drip line would be the place on the ground the water would drip from the tips of the branches furthest away from the tree trunk.

• Tree Fertilizer Spikes: If you have just a few small to medium sized trees, these actually do a really good job. They provide your tree the fertilization it needs. Usually these are put out in a grid with equal spacing, simply follow the spacing instruction on the package. Mark your irrigation and outdoor lighting first to make sure you don't accidentally damage it with the spike. 
  
• Deep Root Fertilization: This is the best method of fertilizing trees. Mychorrhizal fungi soil drench and preventative insecticide can be added which will further help your tree beyond regular fertilization. Every injection point also loosens the soil which allows air and water to move more free to the roots. The problem with this method is it requires professional equipment that is out of reach to nearly all home owners.
  
• Granular Fertilizer: Do not use granular fertilizer on a tree. It will get absorbed by any other plants growing on the soil. Instead of a stronger tree you will probably have really green grass or really big weeds. 

WHAT TYPE OF TREE FERTILIZER

Organic fertilizers and amendments are naturally occurring  Examples are peat moss, compost, saw dust, bone meal, manure. These will not only increase the nutrients in the soil, but will help reduce compaction and allow water to be held better. These fertilize the soil as they decompose so it is less of an immediate effect.  The good news is they will be there for a while so your tree will continue to benefit from them for much longer than alternatives. They also contain less salts than inorganic produced fertilizers.  
Inorganic fertilizers are cheap and scientific so you know exactly what you are getting. These are the most widely used for tree fertilization and get the job done.

Three things we recommend are nitrogen, mychorrihizal fungi drench, and a systemic insecticide labeled for your tree.  Aside from that, you should rely on the soil test results. Be sure to retest the soil near your tree every four to six years to see how you need to adjust your fertilization plan.

*If your tree has a fungus problem, treat the fungus before fertilizing as fungus will thrive on nitrogen.  



If you live in the Greater Baton Rouge, Greater New Orleans or anywhere in Southeast Louisiana, please feel free to call us at 225.752.2333 and have us help you in person.