On a recent visit to McLeod Farms in McBee (oh, the turnip greens I brought home!), fourth-generation peach grower Kemp McLeod told me he waits until the end of January to begin pruning his more than 100,000 trees. You may wonder why he lets December’s sometimes warm, sunny days go by until the vagaries of February roll in to start those long hours of outdoor work. The answer is that pruning stimulates new growth and that shouldn’t begin until the chances of a late frost are past.
In the temperate areas, our woody plants have a period of resting during the winter months. Many lose their leaves while others simply shut down top growth as a way to protect tissues from cold damage.
Some plants, peaches among them, actually go completely dormant and require a certain number of chilling hours before they can start growing again. That’s why they don’t grow peaches in Florida!
Other plants become quiescent. As soon as the environmental conditions for growth return – shorter nights, warmer weather, more rainfall – they start above-ground growth again. Unlike peaches, they don’t have an internal clock that registers how many hours the temperatures have been below a certain number. Sometimes they get fooled into sending out new leaves too early, only to have them zapped by a late freeze.
The roots of plants don’t go dormant; whenever the soils are warm the roots continue to be active.
That’s why fall is the best time to plant as the roots can grow and become somewhat established in their new location without having to send any nourishment upward.
The terminal bud of a stem or branch produces hormones that prevent buds below it from developing and competing for light from the sun and nourishment from the roots.
Fortunately, if that bud is removed, then the buds below can develop into leaves and stems and branches. That’s why pruning stimulates growth. Pruning too early can trigger those “freed up” buds to develop into new leaves that are tender and very susceptible to frost damage. Then the plant must use more stored carbohydrates to replace them with another round of bud development.
Another reason to delay pruning until late winter is the recovery process. Pruning cuts are wounds! They have to heal. Once the soils and air temperatures have warmed and rainfall increases, the plants begin regrowth and those open sores start to heal up and, well, bark over. There are snake oils sold that supposedly help seal pruning cuts, but research has proven that they don’t do anything except take money out of your pocket.
So what’s a gardener to do on the occasional balmy winter day? Check your mulch. If we get those frigid January and February – maybe even March – days, a 3-to-4-inch layer of pine straw or other mulch will protect the roots of your plants.
Also, if it’s going to be cold and windy, be sure your plants are well hydrated. Turn on those hoses and sprinklers. Remember that the large trees that are your most valuable assets, even those that are deciduous, have living roots that need water during the winter when Mother Nature forgets to turn on the spigot.
While you’re involved in hydration therapy, remember that birds often have trouble finding water during the winter, so keep a basin of fresh water out for them, too. I think the possums and raccoons appreciate it, too.
Amanda McNulty is an associate extension agent for the Clemson University Cooperative Extension Service and the host of “Making It Grow!” broadcast weekly on ETV television stations. Website: www.clemson.edu/extension/hgic/. Check out her blog at the Making it Grow! page at www.scetv.org.