John R. Pyzner | 4/19/2005 10:28:29 PM
Now that blueberry harvest is over or nearly over, this is not the time to ignore your blueberry bushes. Taking proper care of your plants after harvest can produce great rewards by producing abundant easy to harvest berries for next year, according to LSU AgCenter horticulturist Dr. John Pyzner.
"Pruning after harvest is an excellent way to control height and maintain bush structure," the horticulturist says.
Rabbiteye blueberry plants generally need only limited pruning for the first five to six years. The main pruning is to remove low limbs and to control excessively vigorous shoots. Vigorous blueberry plants can approach 8 or 9 feet in height after five or six years of growth.
"If efforts are not made to control plant height, the fruit-producing area of the plant will move up to the point that it is difficult to harvest the fruit," Pyzner points out, adding, "Pruning after harvest and before August 1 will generally allow the new growth an opportunity to produce flower buds before winter." He says this will allow the grower to keep the blueberry bushes at a height easy to harvest without sacrificing the following year’s production.
New shoots that will grow beyond the desired height can be cut back to a height of no more than 6 feet. New shoots shorter than 6 feet can be cut back to half their length. Very vigorous shoots developing from the ground should be cut back to 18 to 24 inches.
Pruning immediately after harvest will encourage branching that will be able to set flower buds before winter. Approximately 20 percent of the bush canopy can be removed each year by cutting out one to three of the oldest canes during the winter. This procedure will completely renew the plant canopy in five years.
The removal of old canes should start when the bushes are 5 to 6 feet tall. A combination of selective summer and winter pruning can keep vigorous rabbiteye blueberries bushes at 6 feet.
Apply fertilizer after harvest. In soils with unknown fertility levels and pH, 1 ounce per year of age of 8-8-8 or 10-10-10 fertilizer can be applied around each bush with an 8-ounce maximum. The fertilizer should be spread evenly over a circle 18 to 24 inches wide around the bush.
"Do not use nitrate forms of fertilizer," Pyzner warns, explaining, "The nitrogen in nitrate fertilizers is released very quickly and can burn blueberry roots." Plants should be watered during the season if adequate rainfall does not occur. Adequate water is essential for proper use of fertilizer applications.
"Pruning, fertilization and providing adequate water of your blueberry bushes after harvest can produce an abundance of easy to harvest fruit next summer," Pyzner says.
For related topics, look for Gardening and Get It Growing links in the Feature section of the LSU AgCenter Web site: www.lsuagcenter.com Additional yard and garden topics are available from an extension agent in your parish LSU AgCenter office.