How to Fertilize River Red Birch Trees

Fertilization of trees supplements the soil around a plant's roots to optimize tree growth. Fertilization provides nitrogen, potassium and phosphorus--the essential macro (major) nutrients plants require. Proper fertilization ensures good growth. Over-fertilization can be harmful to roots and should be avoided. Young river red birch trees (1 to 3 years) are best given a small amount of fertilizer. Mature trees may need none.

Things You'll Need

• Sharp shovel, preferably pointed or tapered type
• 16 oz., 8-8-8 or 10-10-10 fertilizer per 100 square feet of root area.
• Small scoop or dirt trowel.

Instructions

Quick and Easy River Red Birch Ferilization

1. Determine the perimeter of the river red birch tree's root system, which typically is found at the drip edge. To determine the tree's drip edge, look up and observe the outer top ends of the tree's branches; the roots' perimeter lies in an imaginary vertical drop from the outermost top edge of the tree branches and leaves. This observation establishes the basic perimeter where the outermost active roots are located for fertilization.

2. Determine eight equally spaced places around this root system's outer perimeter.
   As an example, if the tree is 10 feet high, and the drip edge extends outward in a 10-foot diameter (area of about 80 square feet), the perimeter of the circle will be about 30 to 40 feet. Spacing of the eight shovel slot holes will be about every 4 to 5 feet.

3. Take the shovel and push it into the soil to establish 6 to 12 inches of depth. Leverage the shovel toward and away from the vertical in a back-and-forth motion to widen the hole. Once the hole is established, proceed to the next position and repeat the process until all holes have been dug.

4. Fertilize each hole. Take a garden trowel, load it with fertilizer, and scatter the fertilizer into and across each hole. Application should be about 1 oz. per hole. Eight holes will yield a total of 1/2 lb. fertilizer for the tree.

5. Cover up hole and space with soil. Water the drip edge perimeter and soak the fertilizer positions thoroughly.

Tips & Warnings

• Do not overload with fertilizer. Less fertilizer is better than more for the root system.

• The drip edge is easy to determine. For larger trees, the rule is to not fertilize every year since most root system of river red birches will seek and find sufficient nutrients.

• Use a sharp shovel. Dig carefully and avoid injury.

References

• Fertilizer Nutrients for Plants and Trees
• How to Maintain a Healthy Birch Tree

Resources

• Tree Fertilization: A Guide for Fertilizing New and Established Trees in the Landscape