Pruning Cold-Damaged Plants May Not Be Prudent

Chuck Woods (352) 392-1773 x 281

Bob Black, (352) 392-1835

GAINESVILLE, Fla.—When it comes to cold-damaged ornamental plants, don’t be too hasty with the pruning shears, says a University of Florida horticulturist.

“Cutting away dead or dying leaves and branches may not be such a good idea,” said Bob Black, associate professor with UF’s Institute of Food and Agricultural Sciences. “With most landscape ornamentals, you can’t tell how much damage has been done until the plant starts new growth in the spring.”

By pruning now, he said, you may cut away live wood that doesn’t have to be lost. Also, leaves and branches that have already been killed by freezing temperatures can help protect parts of the plant that have not been damaged.

“If you cut live wood, later freezes will do more damage than would have been done if dead parts had been left on the plant,” Black said. “If you’re determined to prune now, remember to cover whatever remains of your plant to protect it during the cold weather ahead.”

With some of the more tender landscape and patio ornamentals, the cold may have killed everything above the soil line. But these plants — including rubber plants, philodendrons, poinsettia and others — may surprise you by sending up new shoots come spring time. So don’t give up on them until warmer weather arrives, he said.

“With azaleas, the cold usually will damage flower buds and stems,” Black said. “You’ll notice bud damage at blooming time when the plant produces few or no flowers. Stem damage will show up later in the spring and early summer when some branches die. That will be the time for the pruning shears — always cut back to living wood.”

Black said you also may see bud damage and some leaf burn on camellias. Buds will either drop from the plant or open only part-way and show a brown center. Leaf damage should not be too much of a problem. As new leaves come out in the spring, the old, damaged leaves will drop off the plant.

Frozen banana stalks and bird of paradise stems may be removed as soon as you can determine how much is dead. Banana stalks become brown and soft when frozen. New shoots will appear from the ground in the spring. With bird of paradise, there is no true stem, only stalks. These will turn brown soon after freezing.

“Remove them or leave them to protect the root system until spring,” Black said. “It is doubtful that bird of paradise plants killed back to the ground will flower in the spring or summer. Following a freeze, it usually takes 12 to 15 months for plants to flower again.”

He said freeze damage to citrus is not easy to determine, since damage to the tree trunk may not show up for several months. With citrus, it’s possible to have limited damage to the foliage and severe damage to the trunk. Trees should be pruned as soon as possible after the extent of damage has been determined.

As a rule, he said you’ll know what the damage is after the second flush of growth following the freeze.

“Most citrus is grafted,” he said. “If the tree is killed back below where the graft was made, the new shoots will have to be grafted again or else you’ll get only small, poor quality fruit from the rootstock. So, if citrus is killed almost to the ground, it probably will not grow back to produce the kind of fruit it used to produce.”

If there already is some cold damage to plants, don’t relax your cold protection measures, Black said. Try not to encourage any new growth on plants and keep them as warm as possible the next time freezing or near-freezing temperatures are predicted.

Finally, Black said, be a little philosophical if you lose one or two of your tender ornamentals. Think of it as an opportunity to add something new to your landscape.



Posted: February 6, 2001

Category: UF/IFAS

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