Harvesting blueberries and blackberries for full flavor

Summer months are the harvest season for blueberries and blackberries, both of which have the potential to grow very well in Kentucky according to John Strang, UK Extension Fruit and Vegetable Specialist. Blue-berries, which are native to North America, are harvested from early June through early August. Blackberries are harvested from mid-June to early October. These delicious fruits offer newly recognized health benefits (high in cancer fighting antioxidants), but best of all, they capture the essence of summer in their sweetness.

Blueberries can be excellent choices for both home and commercial growing. They have the advantage of being as long-lived as fruit trees, with few pests or diseases. Blueberries are one of my favorite fruits and are great for eating fresh or putting on breakfast cereal. They also have a late blossom time, so frost rarely causes damage on well-chosen sites. Blackberries also have a long fruit-bearing life and will produce for a decade or longer in Kentucky.

Blueberries require an acidic soil, which means that most soils will need to be amended to properly suit their needs. They also require a high organic material content, so peat moss (do not substitute other materials) should be mixed with the soil at the time of planting. Irrigation is necessary during the summer because blueberries have a shallow, limited root system. Insufficient irrigation can compromise both this year’s and next year’s crop.

Blackberries need to be pruned, fertilized and irrigated. Pruning varies, depending on the type of bramble; for specific information on the proper pruning for your blackberry canes, see the University of Kentucky’s publication “Growing Blackberries and Raspberries in Kentucky.”  It’s available online at
http://www.ca.uky.edu/agc/pubs/ho/ho15/ho15.pdf.

Blueberries in a cluster do not ripen at the same time, and only fully ripe berries should be picked. Fruit need at least one to two days after turning blue to develop full flavor and can be left on the bush for up to 10 days without a loss in size. Flavor does not improve once the fruit is picked; consequently, blueberries should be left on the bush for as long as possible to develop sweetness and flavor.

For best results at harvest, pick carefully, rolling blueberries from the cluster with the thumb into the palm of the hand. Handle as little as possible to avoid rubbing off the bloom (the light waxy finish on the skin) and reduce bruising. Harvest only when berries are dry. Refrigerate promptly to slow ripening and decay.

Blueberries are a favorite of robins, thrashers and other birds. You may need to cover bearing plants with re-may, canvas or shade cloth while harvesting your berries. I tried netting last year and it was not very effective in keeping out the birds. It also snags on the branches and is very difficult to cover the plants.

Blackberries picked for commercial sale are picked “firm ripe,” but home growers have the luxury of picking soft, fully ripe and juicy fruit. Pick fruit twice a week, and during hot rainy weeks, every other day. Harvest after the morning dew has dried. Pick carefully to avoid bruising the fruit, and, as with blueberries, refrigerate quickly to limit fruit rot. The sweetest, best tasting fruit is produced during dry sunny weather when nights are cooler.

For more information, see UK’s publications on growing blueberries and blackberries available online at http://www.ca.uky.edu/agc/pubs/ho/ho60/HO60.PDF and http://www.ca.uky.edu/agc/pubs/ho/ho15/ho15.pdf, or contact the Trimble County Cooperative Extension Service at 502-255-7188.

Source: John Strang, UK extension fruit and vegetable specialist

Michael Pyles is Trimble County’s Cooperative Extension agent for agriculture.