Dan Gill's mailbox: Go easy on the pruning for tropicals showing freeze damage (2024)

We have had some freezes here on the north shore this winter, and some of my tropicals have been damaged. I have some cannas, elephant ears, bananas, hibiscus and an angel trumpet that show various degrees of damage. Is this a good time to cut them back? — Joe Johnson

I’ve been getting numerous questions from gardeners about how to handle their plants as a result of the freezes. Generally, do not prune anything for several days after a freeze because it often takes several days for all of the damage to be evident. But it's been a while since our last freeze, so feel free to prune now.

Damaged growth on herbaceous or nonwoody plants such as cannas, elephant ears, birds-of-paradise, begonias, impatiens, philodendron and gingers can be pruned back to living tissue. This pruning is optional unless the damaged tissue is oozy, mushy, slimy and foul-smelling, in which case it should be removed. Make sure you have the base of your plants well mulched with several inches of pine straw or leaves to protect the crown of the plant and below ground bulbs, rhizomes and roots. Even if future freezes kill the plants back, most will regrow from the lower parts.

Remove the damaged foliage from banana trees but do not cut back the trunk unless you can tell that it has been killed. It will look brown, feel mushy, loose in the soil and will bleed a lot if punctured. It hasn’t gotten cold enough yet to kill the trunks. Any banana trees in a clump that produced fruit this past year can be cut back to the ground now, as those individual trees will not produce any more new growth.

Dead leaves on woody tropical plants,such as hibiscus, angel trumpet, croton, ixora, schefflera, copper plant and rubber tree, can be picked off to make things look neater. If you can clearly determine what branches are dead on a woody plant you can prune them back. Try scratching the bark with your thumbnail. If the tissue underneath is green, it’s still alive. If the tissue is tan or brown the branch is dead. Start at the top and work your way down to see how far back the plant was killed.

Generally, it’s a good idea to delay hard pruning of woody plants until new growth begins in the spring and you can more accurately determine which parts are alive and what is dead.

Remember, we are likely to see additional — and possibly more severe — freezes before it’s all over, so stay alert to weather reports and take appropriate steps. Move container plants into protected locations and protect plants in the ground with covers when needed.

This spring, don’t be too quick to dig up tropical plants that have been severely damaged and appear to be dead. They often eventually resprout from the base of the plant or the roots in April or May.

We have a young cypress tree on the front of our property. I don’t know the exact age of the tree, but it’s much shorter than a telephone pole. We cannot stand up under the tree due to the lower branches. Can these branches be removed? If so, when and what is the procedure? Do we have to seal the cuts? — Judy Hymel

You may prune the lower branches from your cypress any time, so prune them now if you like. This is commonly needed when shade trees are grown here.

Branches never move higherfrom the ground than the point they originate on the trunk. To create a canopy that is high enough to walk under, it is usually necessary to gradually prune off the lower branches as time goes by and the trees grow taller. Don’t remove too many branches from the tree at one time. Remove a few branches each year until the canopy is at the desired height.

Generally, maintain about one-third bare trunk to two-thirds leafy canopy as the young tree grows. You do not need to paint the wounds where the branches were removed.