Do we really need to fertilize our trees too?
If you live anywhere other than undeveloped countryside, the answer is yes! However, it’s easy to understand why this service can be overlooked by homeowners when anyone can look out in the country at all the healthy, beautiful native trees growing fine on their own.
For the most part, as long as the soil is healthy, the trees growing from it will be healthy as well. Did you know that when we start adding landscaping, turf and concrete to a property, we might make it look prettier, but we also change how all of these things interact with each other. Trees in urban landscapes usually need additional help to get all the nutrients they need to thrive. One way that trees get their nutrients is from the leaves they shed in the fall. Once those leaves decompose, they provide an additional layer of organic material, which provides nutrients over time that feed the soil. Of course, not every homeowner has the option to let those leaves sit on their yard all winter long. Sometimes HOA’s have rules requiring leaves to be raked, or maybe you just don’t like having that mess and want it cleaned up. Other reasons for raking are unavoidable and you don’t really have a choice. For example, my wife told me that I have to rake the leaves at our house. She didn’t care much about the “natural organic material,” and just wanted it bagged up. So if you’re like me, you might be asking yourself, “How do I replace those lost nutrients?”
The nutrients required for healthy trees are the same as needed for healthy turf; nitrogen, phosphorus and potassium (NPK). Tree roots and grass roots compete for the soil’s nutrients, which means the deeper tree roots are often left hungry when a homeowner only fertilizes the surface of the soil. Trees actually require a higher rate of NPK than turf, however applying that higher rate on the surface would not only damage the turf, but prevent all of the nutrients from traveling far enough down to the roots to be absorbed. To ensure the nutrients get deep enough and are applied at the correct rate, we inject pressurized liquid fertilizer about 12 to 14 inches in the soil. The pressurization breaks up and aerates the soil, providing much needed oxygen to the root system as well. Tree roots are opportunistic and will develop wherever oxygen, nutrients moisture or space are present. Even through that crack in your sidewalk, unfortunately.
So what can you expect to see after our deep root fertilization? Your trees will have a much greener leaf color and thicker foliage. They will benefit from improved disease and drought resistance, healthier root growth, and additional protection against damage in the winter. The only drawback is that next fall you will have even more leaves to pick up unless you can convince your spouse otherwise. If anyone does manage to get out if it, please write in and let me know how you did it. If I don’t respond, I’m probably raking.