Take heart. That pitiful looking, cold damaged plant might not actually be dead!

After all the talk about mild winters the last few years, we finally got a week of weather that makes us wonder if we ought to pack up and head south. All of those tropical and subtropical plants rated as marginally cold hardy for our area are going to be telling some tales over the next few months — mainly if they can really handle a prolonged cold snap.

Depending on how much of a gambling gardener you are and how far you push the horticulture envelope, you might be wondering if your yard is a total loss or just experiencing a minor hiccup. Unfortunately, you’ll have to wait a while to know for sure how much damage you sustained, but maybe this article can help you come up with an immediate action plan and get an idea of what you might expect.

Now, I have to add a little disclaimer before I continue — plant responses can be unpredictable. You can have two of the exact same plants on the same property that appear to have been subjected to all the same environmental conditions and one does fine while the other fails; plants don’t read the rule books.

Herbaceous plants

If you had warm season annuals or perennials such as impatiens, pentas, coleus or colocasia, they probably look like a blowtorch hit them. Brown-black mushy stem and liquefied leaves are a normal response to cold temperatures. The good news is that if the crown and roots are not damaged, these plants might come back next year. Remove the mushy plant parts so that the crown is not staying wet; this helps reduce the potential for rot, which would prevent regrowth in the spring.

Woody plants

It can be a little hard to tell if you have true dieback on woody plants, especially if they are deciduous (drop their foliage yearly), but a good way to check is to scratch the stem with a fingernail and look to see if the tissue underneath is green. If it is green and there is some flexibility in the stem when you bend it, it’s still alive. If the stem is brittle, brown, flakes off or breaks easily, that tissue is dead and will not regenerate. Dead branches can be removed at any time; there is no rush unless there is splitting that might impact healthy tissue or there is a safety hazard by risk of detachment during future storms. Check the crown of shrubs for mushy herbaceous tissue, and remove if present.

Palms

Days after freeze: You might see some necrotic (dead) tissue on fronds. This could be any part, but the older ones (lower canopy) are more susceptible. Leave them on the palm if there is any green tissue left and/or if there is still a possibility of more cold weather. Any green in the frond means it is a nutrient source for future fronds if the vascular system is still functioning. The frond might also offer some protection to the meristem (only growing point in the palm!) from cold weather, so if we are not past our last possible frost date (mid-April), it is best to leave the fronds in place.

Months after freeze: Trunks can be damaged by freezing temperatures, but it is not usually obvious right away. Soft, sunken spots might appear, along with signs of a fungal infestation. The soft spots are where cold damage occurred and the fungi are usually saprophytes, which feed on dead plant tissue. The fungus is not a disease in this case, just a decomposer as it breaks down the damaged trunk. Unfortunately, if the damage was severe, the vascular system of the trunk can be affected, which would present symptoms of canopy wilting. Extensive trunk damage can compromise the stability of the palm and in severe cases result in trunk collapse. Watch palms for wilt symptoms and fungal growth on trunks, and manually inspect for soft areas that could indicate tissue death and decay. Trunk symptoms might not be present for months or even years after a hard freeze.

Another cold damage symptom seen in palms months after exposure are distorted, deformed leaves. Palms have one growing point that develops all of the leaves you see in the canopy. The new spear leaf you see today will show impacts that occurred 4-9 months prior to emergence! A palm that has suffered cold damage might do nothing for months then start producing either normal or damaged leaves. The best bet is to just be patient and as long as there are no signs of an unstable trunk give the palm time to show if it will recover.

How do you prevent cold damage in the future?

The key is to choose the right plant for the right place and follow recommended fertilizer, water, pruning, and mulching practices. Long term best management practices can help plants withstand that occasional freezing Florida winter!

Julie McConnell is the horticulture agent with UF/IFAS Extension Bay County in Panama City. Reach her at 850-784-6105 or juliebmcconnell@ufl.edu. To learn more about these topics and upcoming events. visit http://bay.ifas.ufl.edu or follow UF IFAS Extension Bay County on Facebook.