Frost Damage on Blueberry Flowers


The combination of blueberries and frost is not one that is particularly pleasant; nevertheless, if you are aware of the temperature range that blueberries can tolerate and how to evaluate the damage caused by frost, you will be able to safeguard your blueberry plants when the weather becomes more brisk. Blueberries, scientifically known as Vaccinium corymbosum, are closely related to both azaleas and rhododendrons and are originally from eastern North America. Blueberry bushes have leaves that are around 3 inches long and range in colour from bronze on new growth to dark green when fully grown to yellow or red in the fall. The shrubs produce small urn-shaped blooms that might be white or pinkish in colour throughout the spring, and their fruit matures during the summer.

Planting at least two different blueberry cultivars is required to ensure proper pollination of the crop. The hardiness zones assigned by the United States Department of Agriculture to blueberry plants vary depending on the type; the blueberry bushes recommended by the Farmer’s Almanac are best suited for growing in zones 3 through 9. Frost may affect blueberry bushes in some areas, but the severity of the frost damage that it causes to the blossoms depends on a number of different conditions.

Blueberry Temperature Tolerance

Even though blueberries are a frost-resistant variety of fruit, they still need at least 140 days without frost throughout the growing season in order to be successful. The amount of cold that different blueberry cultivars are able to withstand varies, as stated by a resource provided by the National Cooperative Extension. The amount of damage that may be caused by cold and frost also varies depending on the stage of development that the bush is in. As fresh flower buds open and grow, the blooms become more susceptible to being damaged by frost.

The majority of blueberry plants need at least some part of the year to be spent in a dormant state during periods of chilly weather. Kinds that cease growing earlier in the season are less likely to sustain damage from late-season frost than are varieties that continue to grow later in the season. Frosts that occur early in the season may inflict particularly severe damage on blueberry plants because: Early-blooming varieties are more susceptible to having their flowers damaged by a spring frost and having their fruit production reduced as a result, particularly if the flowers have only partially opened.

Choosing Varieties for your Climate

The optimal environment for producing blueberries is one that either does not experience frost at all, experiences frost only on an infrequent basis, or experiences frost for relatively brief periods of time. Highbush blueberry types need some winter cold, although it is best if they are not subjected to freezing temperatures too early in the season. According to the Farmer’s Almanac, these kinds may be grown in zones 4 through 7, and they are suited for those zones. Their fruit usually matures between the end of spring and the middle of summer. The lowbush cultivars (which may be grown in zones 3 through 7) are more resistant to the cold. And highbush cultivars may be crossed with lowbush species to create half-high hybrids. Half-high cultivars are ones that the Ohio State University suggests growing in exceptionally cold winter circumstances.

You will have the greatest chance of preventing frost damage to your blueberry plants if you begin by selecting blueberry kinds and cultivars that are able to thrive in the shifting temperatures and seasons of your area. However, there is a good chance that blueberries and frost may come into touch in your garden. This is particularly true if you are cultivating blueberries in an area of the United States’ northeastern region where they are indigenous.

Frost Damage and Protection

Frost damage to blueberry plants often becomes most obvious after the blooms on the plant have completely opened. Frost-damaged blooms can exhibit symptoms such as having a water-soaked appearance, shrivelling, dropping from the plants, and having brown pistils, according to the North Carolina State University Extension. If the pistils are brown due to frost damage, then they are unable to pollinate; therefore, the entire blueberry bush cannot set fruit unless only a few pistils sustained damage. However, in this scenario, the fruit matures later than usual and is far smaller than it would normally be.

You are able to take precautions to prevent blueberries from being damaged by frost. For instance, the North Carolina State University Extension suggests maintaining a healthy balance between early and late-season trimming in order to reduce the susceptibility of bushes to damage caused by frost on new growth. The NCSU Extension advises keeping the soil wet because, during the day, moist soil is better at absorbing heat than dry soil is, and at night, moist soil is better at conducting heat to plants. In addition, you may put floating row covers on your blueberry plants. These covers enable the plant to retain heat. You’ll be able to plant the finest blueberry kinds for your location and safeguard them throughout the year if you take these precautions and have some knowledge about the temperature tolerance of blueberries.