Tree Fertilization & Soil Amendments in Phoenix, AZ

Trees don’t always show signs that they need fertilizer until it’s too late. But there are a few warning signs that you can watch out for. If you see any of these signs its time to call a Tree Theory certified arborist to come take a look.

Fertilizing Trees in Phoenix is necessary if you see the following:


  • Smaller than normal leaves – It may be hard to notice, but if the  leaves grow smaller with each year, that’s often a sign that the  nutrients in the soil are being used up.
  •  Yellow Leaves – In fall, leaves tend to turn yellow. But in spring and summer, the leaves are almost always supposed to be green. If you have yellow leaves early, before they traditionally occur, you may have a nutrition problem and your tree may be in need of fertilizing.
  • Trouble Growing – Every year, your trees should grow, branches should expand, they should get leaves – they should even get ever so slightly thicker. If this doesn’t occur, it is possible that your trees simply do not have the nutrition they need to continue growing.
  • Young Tree – Not every tree needs to be fertilized simply because it is unhealthy. However, it is good practice to fertilize established, young trees to make sure that they are able to continue to grow at an adequate speed.
  •  If the leaves fall off of the tree early, or something simply seems off about the tree, it is also possible that the tree simply needs adequate fertilization, and if there are signs that your lawn was in desperate need of fertilizer, there is also an increased likelihood that your tree does as well.

Did you know that fertilization is one of the most overlooked things you can do to improve the health and vitality of your trees and shrubs?   

Fertilizing trees is often best left in the hands of experts since trees are surprisingly sensitive and not all trees should be fertilized. That being said at Tree Theory we specialize in diagnosis and fertilization of your Tree, Shrubs, and flowerbeds. 

To combat the elements, Tree Theory has developed a proven regimen that includes a blend some gentle fertilizer compounds, including bio stimulants such as Mycorrhizae and other beneficial fungi, a soil surfactant which is a soil conditioning compounds that improve the availability of water and nutrients to penetrate the soil, Humic Acid to promote soil micro-organism health and a rooting agent to improve root growth.  We use different variations of our compound to treat trees with disease or to just make sure your trees and shrubs stay healthy.


Our application process it typically through a process called deep root feeding. We inject the blend directly to the root system around the drip-line of the tree or shrub. We believe “Happy Roots makes Happy Shoots”.

Trees and shrubs growing in their natural environment rarely display symptoms of nutrient deficiency. This is due not only to the natural recycling of nutrients that occurs in nature but also to the fact that plants in the wild typically grow only where they are best adapted or have a competitive advantage. Most would tell you that native trees need no maintenance. That is not true. Once you take them from their natural setting its something altogether different. Native trees are also not used to being trimmed which causes them stress. A proper fertilization process will make all the difference in the world. What goes on below the soil is very important to what happens on the surface.

Nursery, street trees, and landscape plantings are what we would consider, an artificial habitat. Soils may be vastly different from those of the native habitat of a given plant, and nutrient recycling systems may be altered or diminished as a result of planting schemes (planting in turf areas) or maintenance practices (collection of fallen leaves). For these reasons, periodic applications of fertilizer to the soil beneath ornamental trees and shrubs is a great idea to replenish essential mineral elements and to promote healthy growth.

In landscapes and field nurseries, it is important to select species that are best suited to the site. A program of cultural practices that sustains or replenishes soil organic matter and nutrients should also be established. These practices might include incorporating compost into soils at the pre-plant stage, applying organic mulches, and cover cropping. Proper maintenance of soil fertility and attention to plant nutritional requirements is at the heart of an effective Health Care program. We are happy to advise you as to what trees and shrubs are best for your property.

Injecting soil amendments and nutrients is the most direct way to get to the root zone!

Injecting soil amendments and nutrients is the most direct way to get to the root zone!

Allepo Pine Blight

Are you seeing brown branches on your Pine Tree? 

Deep Root Feeding Process & Soil Amendments

The best way to get nutrients directly to your trees root system is deep root feeding.   The compound is injected 6 inches below the surface.