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An unusual cold snap has already hit this year. Let's get your plants ready for the next one.

If you blink, you might miss fall in south Louisiana. It seems like we zoomed from summer straight into a deep freeze.

While milder temperatures have returned, it's a good time to talk about how to care for freeze-damaged plants. We dropped to 24 degrees, breaking low temperature records for this time of year dating to 1907.

If you were caught off guard and your plants suffered freeze damage, you can do some things to help them recover. After short-lived light freezes, plants can usually come back. After long, hard freezes, there’s no guarantee.

How do you know if a plant has been damaged by a freeze? Most tropical plants will lose turgidity, become droopy or shriveled and look like they need water. The foliage will turn from green to brown or purple.

After an extended hard freeze, plant stems may split and peel. If that happens, the plant is most likely dead.

In extended hard freezes, the water in between and within the cells of the plants freeze, causing the cells to expand and rupture, resulting in damaged plant tissue. This type of damage is typically irreversible. You will see this most often in tropical plants, such as hibiscus, cannas, pentas, vinca, angel’s trumpet, banana trees, gingers, succulents and cassia trees.

So what should you do? First, be patient. Do not go straight for the pruners and cut everything back. It takes several days for plants to show just how damaged they are.

If plants are mushy and slimy, remove this material to prevent fungal infection or disease in the days to come. You may cut out the dead material to clean things up. For woody plants, wait until spring. You can check for life on woody plants and perennials by scratching the bark of stems and look for green color underneath. If you find green, you’re in luck. Your plant is still alive.

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If you covered your plants, remove the plastic or sheets on warm, sunny days. They will need plenty of sunlight to photosynthesize and stay healthy. Remember, plants make their own food from energy from the sun. 

If you weren't ready for that first freeze, now is the time to prepare for the next one.

Tropical and subtropical plants that have tender herbaceous foliage are the most susceptible to damage. If they can be moved, bring them indoors or into a garage. You may choose to move them under a patio and cover them with plastic or sheets all the way to the ground. This helps trap heat under the cover and prevents frost from forming on leaves. Leave the light on to help generate a very small amount of heat.

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Additionally, you should water plants, especially container plants. Water is an insulator, and wet soil will be warmer than dry soil.

Mulch also helps to insulate the roots of plants. Loosely pack straw or pine needles around the base of plants.

Email questions to gardennews@agcenter.lsu.edu.