This is January. Blueberries are not supposed to be blossoming. Daffodils are not supposed to be growing flower buds, let alone be sprouting up out of the ground. Azaleas are blooming — and not just the Encore varieties, the old standby Indicas are in bloom as well.
If the weather would just gradually and steadily cool down and stay cold for the winter and gradually warm up toward spring, these plants would not be getting fooled. But the swings in temperature are a bit wacky (that’s the technical term) this year.
Two major issues this seesawing of temperatures week to week cause are increased risk of freeze injury through the winter and loss of bloom and/or fruit next growing season.
When temperatures cool gradually, the plant slowly loses water from its cells, which increases the concentration of salts and sugars in the cells, which in turn acts like an antifreeze and reduces the risk of tissue injury when the seasonal low temperatures are reached.
When the weather becomes unseasonably warm the plants start coming out of dormancy. One of the first noticeable indicators of the end of dormancy is the swelling of buds, which is caused by increasing the water content of the bud. This also makes the bud more vulnerable to freeze injury because some of the anti-freeze protection is lost.
All the plants starting to come out of dormancy now are set up for significantly more injury when a freeze does occur than if they had stayed dormant. It is generally acknowledged that next year is going to be a bad year for blueberries in Georgia.
Chili and Argentina have suffered setbacks in their blueberry harvests thanks to El Niño. California can use all the water El Niño can bring to break the drought and fill its reservoirs. But here in Georgia, it has been so warm that the number of chill hours needed to set flower buds is way behind normal. Taken together, the low chill hours and increased susceptibility to freeze injury are setting us up for a no-bueno blueberry year.
This will probably not be the best year for azalea blooms in Savannah for St. Patrick’s Day, but I doubt anyone is canceling their plans to visit because of that.
At your house, the freeze issues are more localized. Citrus should be covered if the forecast is for 28 degrees or lower. Small trees can be protected by putting a 5-gallon pail of water next to the tree and covering both the tree and pail with a large cardboard box that covers the tree and sits on the ground. I recommend anchoring the box and covering it with a tarp to keep it from getting wet with dew or rain and from getting blown over by the wind. Take it off when the temperatures rise above freezing.
For larger trees, I use my expandable canopy I use at the beach and cover that with a tarp. If your citrus is too tall to reach the fruit, then your tree is too tall. Don’t prune it now, prune it this coming spring after the frost-free date.
For this winter, if it gets down to 25 degrees, pile soil or mulch around the stem of the tree deep enough to cover the graft union and water the soil or mulch the evening before the freeze. Your objective is to save the graft union so you have a scion to regrow any damaged twigs and branches. After the threat of freeze is past, remove the soil or mulch to restore the exposure of the top of the root crown to air and the UV of the sun.
Bring hanging baskets into the garage overnight or until the threat of a freeze is past.
Covering plants with a bed sheet that is not sealed to the soil all the way around and that does not have a pail of water under it is generally a waste of time. The idea is to build a small mini-greenhouse and trap the heat of conversion from the water as is freezes. The trapped heat keeps the plant(s) from freezing. If the edges of the sheet or tarp are not sealed, that heat is just gone with the wind.
Less attention to detail than that is making the Rhett Butler statement: “Frankly, my dear, I don’t give a damn.”
Gardner is a University of Georgia Extension agent who lives in Ellabell.