How to Trim a Hemlock Hedge

Hemlock hedges require regular pruning in order to maintain a desired shape and to encourage dense foliage growth. You will need to begin pruning the hemlock hedge from the time you plant it so that the foliage fills in heavily and doesn't become thin or scraggly. Pruning must continue at least twice a year throughout the life of the hedge.



Hemlocks, attractive evergreens with sprays of needle-like foliage, grow continuously throughout the spring and summer. As a result, you can prune these hedges any time, making establishment and maintenance a less-tedious task than training other evergreen shrubs as hedges.

Things You'll Need

• Pruning shears
• Hedge shears
• Electric, battery- or gas-powered hedge-trimmers (optional)

Instructions

Establishing a Hemlock Hedge

1. Remove any dead hemlock branches.

2. Trim away any branches that cross or rub.

3. Cut the shrub to a height of 6 inches from the ground.

Pruning Established Hemlocks

1. Cut the sides of the hedge, making the base wider than the top. This will allow sunlight to reach more branches and encourage thicker growth. Prune the hemlocks once new growth reaches 6 to 8 inches, and cut back new growth to within 2 inches of the last pruning cut you made.

2. Stand back to check your work to make sure the hedge is even and symmetrical.

3. Trim the top of the hedge.

4. Brush cut branches off the hedge and remove them from the area around the shrub. Pruned foliage can harbor disease and insects that might afflict the hemlocks.

Tips & Warnings

• Because hemlocks grow throughout the growing season, you can prune them any time, including during the summer. They will tolerate the heavy pruning that is needed to establish formal hedge shapes; unshaped hemlock hedges will require very little pruning, because hemlocks develop an attractive shape naturally.

• Be patient. Dense, attractive hedges develop slowly, so don't try to force a hemlock to grow quickly into the desired shape. Doing so can result in bare spots.

• Electric, battery- and gas-powered hedge-trimmers make easier work of long hedges. If you use electric clippers, drape the cord over your shoulder so you don't cut through the cord. Plug the trimmer into a safety socket with a residual current device or circuit breaker, in case you accidentally cut through the cord. Whether you use electric or hand shears, keep the blades sharpened.

References

• "Eastern Trees"; George A. Petrides and Janet Wehr; 1998
• University of Minnesota Extension: Pruning Trees and Shrubs
• Colorado State University Extension: Hedges for Landscapes
• University of Missouri Extension: Pruning Ornamental Shrubs