RODALE NEWS, EMMAUS, PA—There's something about this time of the year that makes people crave pruning more than vampires yearn for blood. With fall garden cleanup in full swing, maybe it's all the raking and mulching that has people going bananas. But before you start hacking at your trees and bushes, take a tip from a seasoned gardening expert. "The rules of fall pruning are simple: Prune nothing in the fall! That’s N-O-T-H-I-N-G! Nada! Bupkiss! Zilch! Zero! Ladies—hide the pruners from 'helpful husbands!'" pleads emphatic gardening expert Mike McGrath, author of Mike McGrath's Book of Compost, and radio host of WYYY FM Philadelphia's You Bet Your Garden radio show. That goes for shrubs and plants as well as trees, McGrath insists. "Hang little signs on your roses that say, 'Leave me alone until midwinter; or even better, spring.' There are no exceptions! Do not prune anything now. Got it?"
Do you feel like you just got scolded by a third-grade teacher? Let it serve as a reminder that fall is not the right time to trim trees and shrubs, even though the fallen leaves have exposed all their imperfections. That's right, put your pruning shears back in the shed for at least a month or so.
Here are some pruning basics, to be used when it's a safer time to trim back trees and shrubs:
• Understand why fall is not prime time for pruning. "As I try to stress every year at this time, pruning them now stimulates new growth just when the plants are trying to go dormant, and this severely weakens the plants," says McGrath. "Plus, if you prune on a warm day, sap rises up into the plant. Then, it drops below freezing that night, and boom—not a pretty sight."
Instead, prune in the dead of winter or in early spring, he suggests. That's if you can't stop yourself. "Spring bloomers can get a haircut right after they finish flowering. But get over this pruning obsession—few plants other than fruit trees actually require it, and most gardeners do too much, not too little," McGrath contends.
Still, proper pruning of overgrown flowering shrubs or fruit trees near your house will help the plants produce more flowers and fruit, which can also benefit wildlife. Doing it wisely can also help trees and shrubs give diseases and pests the cold shoulder. Just remember…don't do it in the fall! Waiting until winter means that most woody plants are dormant, and because leaves have already fallen, it makes it easier for you to see what you're doing. For early spring bloomers (like lilacs and spireas) that only need light pruning, prune them just after they finish blooming. For very overgrown deciduous shrubs, winter pruning is probably best.