How to Shape Hedges: a Guide

Trimming a hedge with an electric trimmer

Good fences make good neighbors, and so do beautiful hedges. To keep yours looking great and doing the job of protecting your garden or yard border, follow these steps.

Know When to Prune Your Hedge

Evergreen hedges have a wide range of pruning times. Follow these guidelines. For Yew, Arborvitae, and Heavenly Bamboo - prune in late winter before new growth. For Japanese laurel, Firethorn, and Privet - prune after spring flowering. For Boxwood and Leyland cypress - prune after new leaf growth. For Holly and Cotoneaster - prune after fruiting.

Deciduous shrubs such as lilac, Rose of Sharon, and forsythia make fine garden hedges, but make poor privacy hedges, as they lack foliage for three to four months of the year.

The other main difference between garden hedges and privacy hedges is that the latter are taller, generally over five feet. Hedges for any purpose should be trimmed in an inverted wedge, with the bottom wider than the top, so sunlight can sustain growth at the base.

How to Shape Hedges

Step 1 - Create a Guideline Matrix for the Width and Height

pruning a hedge with manual trimmers

Purchase stakes the desired height of the hedge. Purchase ample string, at least a 1000-yard spool. Measure the desired width and height of the hedge with a tape measure. Place the stakes in pairs on either side of the hedge at one-yard intervals. Tie strings across the top of the stakes so they are level. Secure the strings to the stakes with duct tape.

Step 2 - Prune the Hedge Vertically

Cut along the level of the string, carefully and neatly, with electric or manual hedge trimmers. Use manual trimmers to fine tune stray twigs. Do the same pruning on the opposite side of the hedge to ensure it is level facing both directions.

Step 3 - Trim the Hedge's Thickness

woman in a row of hedges

As the hedge grows it will get wider as well as taller, so prune it next for depth. Remove intervening stakes from the guideline matrix so you can put them at the start and end of a section to be thinned. Lift the stakes and string to the top edge of the hedge. Lay the string on top at the point to which you want to narrow the hedge depth. Cut in the inverted wedge shape: start at the bottom of the hedge and trim upward on a slight angle toward the guideline string. Cut in narrow sections, maintaining a uniform depth. Follow the same process on the far side of the hedge.

Step 4 - Clean up Thoroughly

Pick up, rake or sweep away all cut leaves, twigs, blossoms and fruit. Check for disease or pests. If any are present, put this debris in plastic bags for trash. If the cut material appears healthy, place in the compost.

Use the same process to create shorter, narrower garden hedges. The time-consuming work of pruning, done with attention to detail and a good guide, will reward your patience. Precise, dense hedges frame your garden and yard elegantly, protect your privacy, and add value to your property when you want to sell.