Pensacola News Journal

For: Saturday, Mar. 9, 2002

By: Daniel E. Mullins

Extension Horticulture Agent

Santa Rosa County

Don’t Prune or Give Up on Cold Injured Plants Too Soon

I step aside this week and offer a column written by Larry Williams, Okaloosa County Extension Horticulture Agent. Larry is a good friend and co-worker who says the following better than I can.

If your landscape plants suffered cold injury from the recent freezes, don’t react too soon.

When landscape plants freeze, the first inclination of most gardeners is to take out the pruning shears and cut away the dead and dying leaves and branches. But this really isn’t a good idea. With most ornamental plants it’s difficult to tell how much damage has been done until the plant starts new growth in the spring. By pruning now, you may cut off live wood that doesn’t have to be lost. Also, the leaves and branches, which have already been killed by the cold, can help protect the parts of your plant that haven’t been damaged. If you cut this away, later freezes will do more damage than would have been done if the dead parts had been left on the plant.

If you’re determined to prune now for some reason, be prepared to cover whatever remains of your plant to protect it if we have another freeze or heavy frost. Even though spring is near, we have at least a couple of weeks to make it to the average date for the last killing frost.

Some of the more tender landscape plants such as banana, cassia, gingers, some types of hibiscus and many of the tropical perennials may have been killed back to the ground. But don’t give up on them too soon. These plants may surprise you by sending up new shoots from the roots this spring. Some of these plants require fairly warm soil temperatures before they’ll produce new growth. Many of the gingers, for example, may not show any sign of life until April or May.

Damage to azaleas may be to flower buds and stems. Flower bud injury will be evident at blooming time when your plant produces few or no flowers. The stem damage will show up later in the spring and early summer when some of the branches die.

Individual stems on some azalea varieties and bottlebrush plants are prone to splitting or cracking during a freeze. These freeze cracks usually run lengthwise on the branch or limb. These injured limbs begin dying during the hotter weather of late spring and summer. When this happens, most people do not associate the dead branches with cold injury. But usually you can follow these dead branches back down into the plant and find the crack or split (if it was caused by a freeze). Dead branches should be pruned out as they occur. It’s best to cut below the split or injured area pruning back to healthy, living wood.

Low temperatures often cause bud injury and leaf burn on camellias. Cold damaged flower buds will either drop from the plant or only partially open showing a brown center. This of course is very disappointing to the camellia grower. On the other hand, leaf damage on camellias usually isn’t too much of a problem. In most cases, as new leaves come out in the spring, the old, frost-burned leaves will just drop off the plant.

Whatever you do, even if your landscape ornamentals have already suffered some cold injury, don’t relax your guard. More cold weather may be on its way. So be prepared to keep your prized plants as warm as possible each time there is the prediction of freezing temperatures. And try not to encourage any new growth until all frost danger has past. This includes delaying any fertilization until new growth occurs. Fertilizing too soon could encourage new, tender growth that would only be damaged by a late freeze or frost.

Finally, be a little philosophical. If you do lose one or two of your tender ornamentals - so what? Worse things could happen. And now you have a chance to add something new - perhaps some species native to our area that are not as subject to cold damage.