Brock: Prune with purpose as weather warms

Published 7:06 am Wednesday, February 7, 2018

Days are getting longer, and it only takes a few days of warm weather to push us, groundhog-like, outside. It’s tempting at this point to get ahead of ourselves on things that should be done in true spring.

For instance, it’s not quite time yet to fertilize lawns or plant tomatoes. But there’s no offseason when it comes to Louisiana gardening.

Now is a good time to prune most dormant trees, but please read the rest of this before you run outside and start hacking away. We’ve all seen the ugly results of “crepe murder,” that awful practice of cutting crepe myrtles mid-branch or mid-trunk. When you think about it, this is the natural result of warm weather combined with pruning with no particular method or reason.

So before you prune, have some goals in mind. Are you looking to improve the tree’s shape? Do you want the tree to be shorter or narrower? Are you removing freeze damage?

If so, pruning can help, but only so much. Extreme changes would require different tree selections (and perhaps a time machine.) Does it need to be thinned, either for aesthetics or air flow? Are there dead branches?

Then pruning may be for you.

First, remember you should almost never cut a branch or limb mid-way. That is, do not leave stubs or stumps that will invite disease. Cut it back to its next nearest junction, just outside the “branch collar.”

This is an area (more obvious on some species than others) just before the crotch where the bark looks wrinkled. The wrinkled part is what will grow over the wound. Trees do not heal like we do, but compartmentalize wounds in this way.

Try not to cut branches more than two to four inches in diameter. Larger wounds take too long to heal or compartmentalize. And while it was once recommended that we apply tar-like spray or goop to the cut, more current research shows this actually hinders the recovery process.

Some fruit trees need pruning to stimulate blooming and fruit production. If this is the case, you generally are going for air flow and letting light get to the leaves. Apples and pears can be cut to one central trunk with others pointing away close to 90 degrees.

You can augment this by tying weights to small branches, tying larger branches to stakes or adding spacers to push them out. Citrus trees usually need little to no pruning or shaping.

Another category of pruning is to remove dead and dying branches or those that rub together and will cause problems later. This can be done at just about any time. But if it’s freeze damage, wait until weather really warms and growth begins. That way you can see what’s really frozen and what will recover.

In any pruning endeavor, don’t be scared to cut. You can take off as much as one third to one half of volume (that you see) without stressing the tree. Keep your goals in mind while making some cuts, then step back and look. Re-evaluate, and then start cutting again. Repeat until you’re satisfied or your spouse starts screaming, whichever comes first. It’s easy to make another cut, but hard to put stuff back on. That’s what my barber keeps telling me.

If you want to know more about gardening landscaping, or anything else horticultural, contact the St. John / St. James Parishes County Agent André Brock at abrock@agcenter.lsu.edu. Also, the LSU Ag Center’s website can be accessed at lsuagcenter.com with lots of user-friendly information, including this article.