Blueberries

Question from Sue:

I live in Santa Ana and my Sunshine Blue blueberries are in full bloom. Will the plants have 2 crops this year or will I lose my summer berry season.

Answer from Pat:

Unusual weather conditions and special micro-climates can force flowering followed by fruiting at unusual times of year not only with low-chill varieties of blueberries but also with other fruits, for example low-chill apple trees. Specific varieties of blueberries and other sub-tropical fruits behave differently from one another since some varieties bear early and others bear late in the season and they vary also as to the amount of winter chill required to cause flowering.The low-chill apple tree, ‘Anna’ bears fruit year-round in some gardens that have a unique micro-climate with wide swings of temperature differences between night and day.

In your case, what most likely caused your blueberries to bloom was a cold snap or several cold nights that satisfied the plant’s need for a period dormancy. The variety you have, ‘Sunshine Blue’, is a Southern highbush and it is evergreen. This variety needs very little winter chill in order to bloom and bear fruit. If the cold snap your plants underwent was followed by warm weather, existing flower buds were thus forced open and subsequently you might get fruit. This is most likely what happened to your blueberries. If another cold snap occurs early next year and if your plants have enough one-year-old wood on which to bear blooms, they might bear fruit a second time in spring, summer or fall, despite the fact that this variety usually bears fruit mid-season, that is in summer.

It will be interesting to see if you get a second crop this year, or even several crops, but if the winter crop is heavy the second crop is likely to be lighter. If your plants are mature and the berries are too small, you will need to prune out some of the older woody tips after harvest in order to force more new wood to grow that will be one-year-old next year. This one-year-old wood will bloom and bear fruit next year.