Happy Valentine’s Day!

I am certain that many individuals reading this column either gave or received a wonderful bouquet of flowers to celebrate the occasion. On the other hand, I’m hoping those with backyard fruit trees don’t see blooms on fruit trees for several more weeks.

In years when the winter weather has remained cold for extended periods, fruit trees bloom too early and get hammered by a spring freeze. Let me explain.

John C. Coccaro is county Extension director. Write to him at 1100-C Grove St., Vicksburg, MS 39180 or call 601-636-5442. E-mail him at jcoccaro@ext.msstate.edu.

Here in Mississippi, the fruit production of peaches, plums and nectarines is reduced or eliminated when frosts or freezes occur following the bloom period. Since the bloom evenutally develops into the desired fruit, growers do not want anything to adversely affect the flower.

What makes the trees bloom earlier in some years? Fruit trees such as peach, plum and nectarine will break dormancy and begin to bloom after they have acquired a certain number of chill hours, regardless of the calendar date. Chill hours are defined as the number of hours the trees are exposed to temperatures below 45. While I have not personally tallied up the total for this winter, I would suspect our trees should have accumulated very near their requirement to break dormancy and to begin to bloom. 

Required chill hours vary by variety. For example, a Contender peach needs 1,050 chill hours, and a Bicentennial only requires 700. If one mistakenly planted a variety recommended for south Mississippi, such as a La Pecher or a La Festival there might really be a problem, as those varieties only require 450 chill hours. Most plum varieties only require 550 to 800 chill hours, so they might bloom very soon and become even more susceptible to injury than peaches. The requirements for nectarines are similar to peach trees, requiring around 800.

If our fruit trees do not sustain a frost or freeze following the bloom period, it actually might benefit the quality and quantity of the fruit production this year. The fruit will be formed earlier in the season and might avoid insect damage or summer drought stress. 

Fruit tree growers might need to alter some management practices this month, especially for fertilizing and pruning. The Extension Service recommends applying about half of the tree’s recommended fertilizer in February and before the buds break. Of course, it is always best to have a soil analysis to determine fertilizer needs. In the absence of soil test recommendations, the general rule is to apply 8 to 10 pounds of a blended fertilizer, such as 13-13-13, per mature tree per year. This should be done now. 

Pruning fruit trees is also recommended before buds break. In most years it can wait until later in February, but this year will be an exception.