Sunday, May 2, 2010

Frost Damage

A long period of extremely warm temperatures during the early spring almost always means that some frost intolerant plant is going to get hit by a freeze. Statistics say that this area still has a 20 percent chance of below freezing temperatures on May 17. During the past five years, we’ve hit the jackpot three times, with temperatures dropping into the upper 20’s during the third week of May. It’s really a disappointment when damage is done to one of the rarities like this Dwarf Hackberry, Celtis tenuifolia. Two mornings of hard frosts have really knocked back the growth on these small trees.

Dwarf Hackberry was loaded with blooms this spring. We could have had a magnificent fruiting year. Now, too many flowers look like this. You can’t even delude yourself into believing this flower is not dead.

Some of the earlier blooms were already producing fruit. I’m going to tell myself that the fruits still have a chance of maturing, but I know that these little green guys will be littering the ground in a few days.

Dwarf Hackberry is a southern species and it has not evolved to be freeze tolerant. Frost kills the leaves and extremely cold winters kill branches. Blue Jay Barrens lays in the northern boundary of the Dwarf Hackberry’s range. The adversity that these plants endure helps shape the genetics of the population, so future generations will be better adapted to the rigors of this climate. The odd growth of these branches is testimony that the tree has suffered similar hardships in the past.

Here’s a little hope to sooth the disappointment. New leaf growth will be evident by summer and there will be some fruits in the fall. The marginal existence of the Dwarf Hackberry will continue with its cycle of growth and diebacks to remain a part of the Blue Jay Barrens landscape.


  1. Yes there is always a chance of frost!! People hear get all excited about the nice days and plant unhardy flowers and wonder why they loss them to a frost!! One year I lost a least 12 tomato plants the second week of June, rare of course but it happens!!

  2. Things are a tad warmer here in St. Louis and the Ozark Highlands south of us. Celtis tenuifolia is well established in the glades and xeric woodlands that occur in many parts of the Ozarks, and I've associated a number of interesting woodboring beetles with the plant.

  3. grammie g - My landscape plants have to fend for themselves and any that can't take a frost are long gone. I usually wait until June 1 to put out my tomatoes. I always seemed to lose my early planted tomatoes because my work kept me from getting home and covering the plants when a frost was predicted.

    Ted - I have several plants here that are also commonly associated with the Xeric Ozark Region. I'll pay more attention to the insects utilizing Celtis tenuifolia and see what I can find.

  4. Could frost kill a plant such as buck brush or slick leaf?

  5. I doubt that frost would do any permanent damage to buck brush. All the leaves might be lost, but unless the bush is really stressed, it will just grow new leaves and keep on going.