Tree Health Tips

It’s no secret that an earth auger can make short work of many hole drilling tasks like fencing, mailbox installs and deck building. But did you know that earth augers are also frequently used for fertilizing and watering trees? Hard packed soils and deep roots make maintaining trees very challenging in some areas but by drilling holes in the earth, you can get the necessary nutrients to a tree’s root system.

Fertilizing

A tree may require attention if it is showing signs reduced growth or smaller discolored leaves. There are several reasons trees may require additional nutrients, the most abundant of which is poor soil quality that is common to developed urban areas.

The most common method for fertilization involves spreading granule fertilizers to the surface of the soil. While this method is simple and quick to apply, it likely will not produce desirable results especially when applied in a lawn or garden where other plants closer to the surface may absorb most of the nutrients.

The subsurface method includes drilling a series of holes around your tree along the drip line. The drip line is used to describe the outermost circumference of the tree canopy. To efficiently deliver fertilizer to a tree’s root system, use an earth auger to drill 2” holes 1-2 feet apart and about 12-18 inches deep along the drip line and add your measured fertilizer equally throughout these holes. Once the fertilizer has been added, fill the rest of the hole with soil. This method prevents surface plants like grass from stealing the added nutrients and has a much lower risk of runoff waste.

Watering

Efficiently watering trees can be done in a nearly identical fashion to fertilizing with a few minor tweaks. Surface watering is very common but in dense, compact soils, most of the water will runoff or be absorbed by surface level plants. To combat this problem, drill 2” holes around the drip line of the tree and fill with pea gravel to allow water to penetrate the soil to the root system. The depth of watering holes can vary but 24 inches will be beneficial to most trees.