Published on 01/20/00

Keys to Proper Pruning: Timing, Tools and Technique

It's time to prune your summer-blooming plants like crape myrtles, nandinas, shrub roses and glossy abelias.

"The keys to proper pruning are timing, technique and the right equipment," said Bob Westerfield, an extension horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.

Prune Summer-Bloomers Now

Prune summer-blooming plants and most woody ornamentals in January through early March. But prune spring-flowering plants like azaleas, forsythia and dogwood soon after they bloom.

"Of course, if you see dead plant material, you can prune that off any time of year," Westerfield said.

Pruning is often necessary for your plants' health. It's a way to remove disease and keep your plants looking good. It can also rejuvenate older overgrown shrubs.

Proper tools are a key to successful pruning.

Purchase a Good Pair of Hand-Operated Shears

"Steer away from gas-powered pruners," Westerfield said. "Hand-operated shears work wonderfully as long as you keep your instruments sharp so they cut the plant instead of tearing it."

Hand pruners are perhaps your most essential pruning tool. "Buy the best quality you can afford and you won't have to keep going back to the store for a new pair every year," he said. "The draw cut or scissor type is the most useful."

The anvil-type, hard pruners aren't as good. They tend to crush limbs rather than cut them.

Use lopping shears to prune small trees or shrubs like crape myrtles with diameters up to 1.5 inches. For plants with branches more than 2 inches thick, use a pruning saw.

Heading or Thinning

Now that you have the proper tools, you're ready to start pruning. There are two methods: heading and thinning.

"Heading is when you shear across the plant nonselectively," Westerfield said. "This method is normally used on boxwoods to give them that formal look." Use heading sparingly, as it causes excess canopy growth.

Thinning is a more useful and healthy cut. "Use thinning to prune out sections of the plant to allow more light and air inside," he said. "The increased air reduces diseases and insects like spider mites."

How you prune determines the shape of your plant.

"If you leave buds on the outside it causes the plant to grow outward and spread," he said. "If you leave buds on the inside it causes the plant to fill out from within."

Let Air and Light In

Westerfield reminds home landscapers to always prune leaving the bottom of the plant larger than the top so that it forms a pyramid shape. "If you don't, you'll cause a canopy affect, and no light will get in," he said.

Make your cuts at a slant, too, and a fraction above the bud. The slant will allow water to roll off the newly cut surface.

Don't use pruning paints. "They're unnecessary and may slow the cuts' healing," Westerfield said.

After you've finished pruning, don't just throw your pruning tools in the shed. Your tools are an investment, and you need to take care of them.

Take Care of Your Tools

"Use an 8- to 10-inch file to sharpen your tools," Westerfield said. "Put your tool in the vice and sharpen at the angle the manufacturer used for the blade. Always sharpen in one direction, never back and forth."

Never use an electric grinder to sharpen pruning tools. The heat build-up can weaken the blade.

Be sure to clean your pruner blades after pruning. "Give them a light coat of household oil, too, to prevent rust," he said.

After all, it won't be long until you have to pull out your tools to prune your spring-flowering plants.

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.