Sid Mullis: Throwing a blanket over plants won't protect them

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Winter officially starts Saturday. For the most part, it has felt like winter arrived the middle of November, in spite of the warmer than average temperatures we had this week. If memory serves me correctly, November was about three degrees cooler than average. This was despite setting a record high of 87 degrees Nov. 18.

We also set a new record for the coldest Thanksgiving ever! We had an official low of 21 degrees. The previous low for Nov. 28 was 22 degrees, set in 1903. As always, our official low at Bush Field Airport is always colder than the rest of the Augusta area. I don’t know how cold it was at my house because I was out of town. I was in Hinesville, Ga. When I got dressed to go out and run Thanksgiving morning, my smartphone said it was 28. That was probably a record for Hinesville too.

We also set a record low of 21 degrees on Nov. 14. I think it got down to around 28 or 29 at my house, and this was the freeze that did in my bell peppers and tomatoes. The last two years I was harvesting bell peppers until the New Year. Even though my tomatoes died on the Nov. 14 freeze, I ate my last homegrown tomato last Monday.

I mention all this cold, freezing weather because many people try to protect plants in containers and in the landscape from getting damaged by throwing a sheet or blanket over them. Doing this may make you feel better, but in most cases you are doing little good unless you anchor it to the ground, creating a mini-greenhouse.

Putting a sheet or blanket over a plant doesn’t create heat like is does on a person. We are warm blooded while plants are not. The only heat available under the blanket would be coming from the soil. Even if the covering did work, the wind could blow it away. Plus, using a blanket to cover your plants may result in broken limbs.

If you really want to help your outdoor plants prepare for the cold, the time to help them the most is in the summer. If you take good care of your plants during the warm months by keeping them insect-free, giving them the correct amount of water and fertilizing them, you help build a hardier plant.

You have to also realize that since outdoor plants are in the elements 24 hours a day, they adapt to temperature changes. When cold weather arrives, it is not a shock to them because they have gradually prepared for it. For many of our plants, temperatures would have to drop below 15 degrees to damage the stem tissue of some zone 8 plants – and we haven’t had it that low in several years.

If you want to baby your plants, save the special treatment for prized possessions such as that lemon or lime tree you bought in a container or you started from a seed. If it’s a one of a kind plant and you really don’t want to lose it, build a makeshift shelter for it.

Container plants are ones that might need babying the most. Container plants are more susceptible to cold temperatures because their roots are above ground.

You can protect your container plants several ways. Place them inside your home, garage, greenhouse or shed. I do a combination of all these things. The ferns on my front porch may go in my garage, while some plants on my deck may go in the house. A couple of plants in the backyard go in my shed.

It also helps to push container plants together, particularly against the house. You can also mulch or cover the sides of the containers to decrease heat loss.

Plants growing close to the ground usually benefit from heat radiating from the soil. Tall, more open plants don’t receive as much heat and are not protected from the cold.

Many times you won’t truly know whether your protective efforts were successful until warmer weather arrives next spring. Plants with cold damaged roots may not show signs of injury until temperatures rise and the plant’s demand for water from the roots is greater.

The overall key to making sure your landscape plants survive each winter is planting the right variety from the start.

Don’t just buy a cultivar of some woody ornamental you’ve heard about or one you think will do good in your landscape. That shrub that does well in central Florida might not make it here. Do a little research and make sure the plant you are buying is suited for our area.

And finally, a well-hydrated plant is better able to withstand the cold than one that is not. Fortunately, with the way Mother Nature works, it typically rains before a cold front moves through. But sometimes we get these “dry” fronts where it rains very little or not at all. In this case, you might need to water certain plants before the cold moves in.

Reach Sid Mullis, the director of the University of Georgia Extension Service office for Richmond County, at (706) 821-2349 or smullis@uga.edu.


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