We have had a mild warm winter but some were wondering if we would get caught with any cold temperatures that could damage fruit tree buds. As the trees begin growth in the spring the buds begin to swell and lose the ability to withstand cold temperatures. As the buds develop, warmer and warmer temperatures (still below freezing) can damage them. The killing temperature is often called the critical temperature and is defined as the temperature that buds can withstand for a half-hour. In general, there is a range of temperatures over which damage occurs with more and more buds and flowers damaged at lower and lower temperatures until all the fruit buds are killed. Often the freeze will only damage some of the flowers such as the most developed ones or flowers in the bottom of the tree.
After a freeze, people often want to know how bad the damage was. It takes several hours for the symptoms to develop. As frozen tissues thaw, they will turn brown or black if they were damaged or killed by the cold, revealing the extent of the damage. This last weekend we did see the temperatures dip into the 13-17 degree range which could have affected stone fruit bloom buds (peach,cherry,apricot,plum). At temperatures of 20-22 degrees there is a 10% damage, at 7-9 there is a 90% damage to blossom buds. So I think there is a possibility of some damage but nothing too significant and the trees themselves are fine.
Apples and pears are very different than stone fruit. The buds of stone fruit trees are either flowers or leaf buds, and not a mixture of both. In cherries and plums where there is more than one flower, all the flowers in a bud are about the same age. In apples, the fruit buds are really small shoots with both flowers and leaves.
Here is a great article to read more https://www.canr.msu.edu/news/assessing_frost_and_freeze_damage_to_flowers_and_buds_of_fruit_trees
I did see some red maples blooming so maybe a reduction of there seeds is possible. Some early crocus blooms got froze.
