All plants need water. As a supplement to fertilizing, trees may need to be watered. Newly transplanted trees need at least 1” of water per week for the first season. This should include both rainfall and additional water. During the first five years of growth, water should be added during any 2 to 3 week dry period when little or no rain falls. Older trees should be watered at least once per month in drought periods. Thorough watering BEFORE the ground freezes is especially important in a dry autumn.
The key to proper watering is to get the water to the ROOT ZONE where it is needed most. (This is the area roughly 3 feet deep under the DRIP LINE of the tree.) The easiest method is to slowly water the surface of the root zone until saturated 1 to 3 feet deep. The tree pit area of a newly planted tree should be thoroughly saturated every week or two during the growing season.
Timing for watering of trees varies with weather conditions and from season to season. The chart below shows the periods of most beneficial watering.
For your newly planted trees, up to one year after transplanting, no fertilizer is necessary since a proper planting soil mixture was used. However, after the first year and each year thereafter, fertilize as follows:
Shade Trees and Small Trees: Use tree spikes with a fertilizer formulation of 16-8-8. Use one (1) spike for each inch of trunk thickness, as diagrammed below:
Evergreen Trees: Use spikes with a fertilizer formulation of 12-6-8. Use one (1) spike for each inch of trunk thickness. (Same principle and procedure as diagrammed above.)
Drive spikes into soil at DRIP LINE of tree.
6” diameter of trunk= 6 equally spaced spikes.
Other Fertilizing Techniques
When to Fertilize
Fertilize once per year, either in the spring or autumn. In the spring, fertilize as soon as the frost has left the ground. In autumn, fertilizer should be applied after the leaves have dropped from the trees. Fast acting (quick release) nitrogen should not be used between August 1st and leaf drop. It may bring on new growth not ready for a cold November or December.
Generally, the ideal time to fertilize is in autumn after the leaves have fallen, bur prior to the ground freezing.