Tree Root Feeding

Graf Tree Care specializes in Plant Health Care, and out of all of our usual applications, root feeding is our absolute specialty in the world of tree heatlh. We have definitely found our niche in specialty root feeding by using the right fertilizers at the right time on the right trees. What may be the right fertilizer, timing and application method for one tree may not be beneficial for another. Over time, we have steered ourselves away from broadcast fertilizers for all trees that can be inefficient for us and our customers both. Let's start by explaining why root feeding is important in the urban landscape.

Soils in our urban landscape are certainly not what trees are designed to even exist in, much less grow and thrive. We have essentially removed the "forest floor" from our trees eco-system. Out in the woods, where trees are native, they receive the necessary nutrition from the decomposition of organic material. In other words, leaves fall, dead branches are shed and they reside underneath the tree where they breakdown and contribute to a soil rich in the macro nutrients: Nitrogen, Phosphorus, and Potassium (N,P,K), not to mention literally hundreds of micro nutrients. As the tree uses these nutrients more are created as more leaves and branches fall each season. This is called "nutrient recycling. Trees, like people will use the nutrients that are readily available, but if nothing is going back into the soil then that soil will become stagnant. By conforming with our cultural norms for landscaping, like raking leaves, picking up fallen branches and having lawn and competing plants under our trees, we have broken the chain of nutrient recycling.  With the proper use of the correct fertilizers timing and equipment, we can re-create what is happening on the forest floor to achieve the highest level of health and best possible appearance of our urban trees.

So now we know that most soils in urban/suburban settings are in poor condition. Natural beneficial organisms have been destroyed by human activity. The soils are often highly compacted, low in organic matter and contain concrete, asphalt and other construction debris. Trees must compete with turf, flowers and other landscape plants for available nutrients and water. Trees are often planted in places unlike their natural habitat with sidewalks, patios, driveways and houses covering up their root systems. With all these factors working against them, it’s a wonder that trees survive at all.  

While traditional chemical fertilizers have their place, and we still offer this service, we have shifted our focus to using bio-fertilizers to improve the root systems and the soil that the trees are growing in. Promoting long term sustainability in trees requires a different approach than using fertilizers high in nitrogen. These type of fertilizers can produce excessive canopy growth, which can lead to problems when trees don’t have the root systems to support the extra growth. We work to rebuild tired, depleted soils and establish beneficial organisms that will create a “naturally renewable” source of fertility. Building healthy roots allow trees to withstand summer heat, drought and watering restrictions. Healthy roots also make trees better able to withstand attacks from insects and disease.  

The bio-fertilizers we use contain mycorrhizal fungi, beneficial bacteria and microbial nutrients.  

• Mycorrhizal fungi: These beneficial fungi colonize tree roots. They form a bigger net to bring in all the major and minor mineral elements and water which they share with the trees. They do this more rapidly and for longer periods than trees can do on their own.
• Beneficial bacteria: These “good guy” bacteria make soil nutrients soluble so that trees can take them in, improve the condition of the soil and provide renewable levels of mineral nutrients.  
• Microbial nutrients: Including humic acids, sea kelp and other high quality ingredients. They enrich the soil and provide a feast for microbes, enabling them to populate the soil and continue to benefit the tree for years to come. These organisms exist in a natural setting that has not been disturbed by human activity. They take fallen leaves and branches and recycle them into the soil. This is why forest floors are so rich in nutrients. What we want to do with our bio-fertilizers is to replicate the way things work in nature. This creates an environment that is self sustainable and supports healthier trees. Healthy trees have less insect and disease problems and require less chemical treatment.  

If you have questions about bio-fertilizers or would like an evaluation and estimate, please contact us.