Bush Pruning Tips for Healthier Bushes

Cane-type bushes, such as forsythia and hydrangea, usually send up new canes from their roots every year. In general, prune out the oldest (larger) wood to control the bush height. It's also OK to trim out newer canes to thin the interior of the plant and let in light, as well as to control spread. If one of these bushes has gotten too big and out of control, you can often cut off all the canes and the roots will send up new shoots. You'll have a nice new bush in a year or two. Note: All bush categories have exceptions to these rules. So know your plants!

The first year, cut the branch tip just beyond a bud. This “heading off” technique channels more growth energy to smaller side branches, which will then fill in vacant areas. Make this cut at a side branch or 1/4 in. beyond a bud. Be selective and watch the results from the previous year to help gauge future growth. This technique works best on bushes and trees that grow mostly from one or a few stalks, as opposed to bushes that continually send up new shoots (suckers), like lilacs and forsythia.

It's tempting to grab the hedge shears and shape a bush by cutting off the branch tips. This “flattop haircut” approach may look fine for a year or two, but it stimulates growth on the outermost branches, forces the bush to grow into an unnatural shape (your idea rather than the plant's) and fails to control size. The bush actually grows larger and becomes more difficult to bring back to size without being ruined. The exception is hedge-type bushes.

If neglected, many bushes get too big and dense. While the foliage might look OK this year, next year it just might be too big to prune back without butchering it. Instead, it's better to control size and shape by selectively pruning out a few entire branches each year. Cut them at a larger branch or the trunk. This also opens the plant to light and encourages healthy growth from the interior.

Unlike cane-type bushes, evergreens and other “nonsucker-type” bushes grow from their existing stems. They develop a more permanent branch framework and usually need less pruning. If your landscaping was well planned, these bushes, especially evergreens, will grow to fit their spot with relatively little help. They'll need only a light annual pruning to remove dead branches and to control size and shape.

It's important to cut or saw branches at the collar— just above where the branch joins the main trunk. The branch collar is the bark swell that encircles the branch. If left intact, this collar will soon grow over and cover the wound. Don't leave stubs. They'll rot and might become diseased.

Don't force a big bush to conform to a small space by pruning. It can be done, but it's easier to pull out an overgrown bush and plant one that will mature at a size that better fits the space.

If you have bushes that you want to remove, here's how to get the roots out without hours of digging and chopping.

Use leverage. Start by digging around the base and cutting all the roots you can get at. Then lay scraps of plywood on each side of the bush. Set a jack stand or concrete blocks on one side and set up your jack on the other. Lay a beam across them and tie the root to the beam with a chain. You'll apply hundreds of pounds of pulling force, so both the beam and the chain must be strong. Use a 6-ft. 4x6 or 6x6 for the beam and a chain for towing cars. Raise the jack, stopping to cut the roots as they become exposed. If you max out the height of your jack before all the roots are free, add a few blocks to increase the beam height.

Caution: Before cutting the roots, reduce tension on the chain to prevent injuries from recoil. Wear eye protection.

Pruning shears are by far the fussiest garden tool to sharpen. The principle is the same as for hedge shears, but filing along the curved blade asks a great deal of your fine motor skills. The other half of the pruning shears has a thick, blunt blade that the sharp curved blade cuts against. This heavier blunt blade is one reason this tool is able to cut branches more than 1 in. thick.

First, file along the factory bevel. File the edge of the pruning blade using two hands. Start at the point and follow the curve of the factory bevel. Make one complete stroke from the point to the base of the blade. Apply light pressure in a direction away from you. Examine the edge after each stroke of the file to ensure you're following the path of the factory bevel. Once you've exposed fresh steel along a consistent curve, feel the back side for burrs. Sand away the burrs.

Then, file the blunt blade so it's flat. The blunt blade needs a crisp 90-degree edge. Think of the edge on a freshly cut piece of granite. Both the top and the side surfaces are flat, and where they meet you'll find a crisp, sharp edge. File along the factory bevel. Using a smooth 10-in. half-round file, file the inside curve of the blunt blade perfectly flat. Use two hands for control. Make sure you hold the file exactly 90 degrees to the inside curve. Once this surface is flat, sand both side surfaces of the blade with 300-grit paper to get rid of any burrs.

Before sharpening hedge shears, check the pivot nut. The nut should be snug with no play. If the shears still cut poorly, look down each blade to make sure it's not bent. If a blade is slightly bent, loosen the pivot nut and separate the blades. To straighten the blade, put it in a vise, slip on some thick leather gloves and tweak it until it's straight.

Next, file the edge to expose clean metal. Examine the factory edge. Hold the file with both hands and mimic the direction of the bevel. Now move the file in one broad stroke away from you along the entire cutting angle. Don't use small, jerky strokes or you'll lose the factory edge. As you work, you can see the clean metal path left by the file. Adjust your angle as needed to file the entire edge evenly. Repeat this motion several times until you expose clean metal over the whole edge. Usually it'll take only about 10 strokes. Do the same with the other blade.

Finally, sand the back side of the blade. Place a sheet of 300-grit wet/dry sandpaper on a smooth, flat piece of plywood. You'll be able to feel the burrs (be careful?they're sharp) on the back side of each blade. To remove them, lightly sand the back side of the blade. Keep the blade flat and move it in a circular motion. After making several circles, pick up the blade and gently feel the edge. When the burrs are gone, assemble the blades and lightly oil the moving parts with 3-In-One oil.

Prune midsize branches without damaging the tree by cutting them in three stages. Make the first cut (1) on the underside about 8 in. from the trunk, cutting a third of the way up. Make the next cut (2) at the top of the branch 3 in. past the first cut.

Finally, cut the remaining stump off at the trunk, just past the slightly raised area, called the branch bark ridge, making the cut perpendicular to the branch to minimize the exposed surface.