Your landscape trees require regular pruning in order to live long, healthy lives. Yet, even pruning can spread disease and pests if proper precautions aren't taken.

1. Trim During Dormancy

The best time to trim a tree is when it is dormant, usually in winter or very early spring. This isn't because it minimizes stress to the tree so much as it is because most pests are also dormant at this time, including both pests and disease organisms. Further, tree growth occurs most rapidly right when the tree awakes from dormancy, so it will quickly seal the wound closed before pests can invade it.

2. Avoid Wet Weather Pruning

Although pruning is best done during winter, choose a dry period in order to do it. This is especially true in late winter or early spring when a quick warm up could awaken fungal spores and bacterial pathogens, which could then infect the pruning wound. If it's dry out, then fungal and bacterial disease are less likely to infect the wound.

3. Keep the Tools Sterile

Your pruning tools, including shears and saws, can transport disease organisms. This can spread in infection in a single tree, or worse, spread the infection to multiple trees. Since some pruning cuts are made to remove diseased wood, proper sterile procedures are a must. You can dip the tools in dilute bleach water or wipe the blades with an alcohol soaked cloth. Sterilize after each cut if you will be moving to a different branch or plant. 

4. Leave a Clean Wound

A messy wound will heal more slowly, which makes it more susceptible to pest or disease attacks. A tree can quickly seal a clean wound, though. When cutting out a whole branch, make the cut right flush to but not through the raised branch collar at the base. For cuts further out, cuts should be made directly in front of leaf or bud. If there is damaged bark, use a sharp knife to smooth the edges of the bark wound and to round any sharp angles. 

5. Clean Up the Trimmings

Never leave the trimmed branches on the ground. If there are any diseases or insects residing on the trimmings, they can spread back into the tree or into neighboring trees. Always clean up and dispose of the trimmings when you are done pruning the trees. 

Contact a tree trimming service for more help with keeping your trees healthy.