Blueberry Culture 



Dominic A. Marini 



Cooperative Extension, University of Massachusetts 



This article gives highlights of a presentation by 

 Dr. Gary Pavlis, Rutgers University, at the New Eng- 

 land Small Fruit and Vegetable Growers Convention, 

 November, 1989. 



In selecting a site for blueberries, look at the natu- 

 ral vegetation- wild blueberries, azaleas, and other 

 acid loving plants indicate a favorable site for blueber- 

 ries. A soil with high organic matter content, good 

 drainage, and which is well aerated is preferred. Heavy 

 clay and poorly drained soils are not desirable. Blue- 

 berries can be under water during the dormant season 

 but not during the growing season. In New Jersey, 

 some blueberries are being planted on ridges on wet 

 soils. 



Mulching is highly desirable. Mulch insulates the 

 soil in hot weather, maintaining lower soil tempera- 

 tures-blueberry roots stop growing at high soil tem- 

 peratures. Mulches also help control weeds-blueber- 

 ries are poor competitors. Mulches conserve soil mois- 

 ture and supply nutrients as they decompose. Disad- 

 vantages of mulches are their expense, labor cost of 

 application, sheltering of mice, and the danger of fires. 



Spring planting is preferred. With fall planting, 

 heaving during the winter is a possibility. 



Cultivar selection depends on your market-pick- 

 your-own, retail, or wholesale. Patriot does well on 

 upland soils in New Jersey; Spartan does not. Bluecrop 

 is the leading cultivar in New Jersey. Eliot is sour 

 when it first turns blue-wait 4 or 5 days to harvest. 

 Elizabeth, Darrow, and Coville have good flavor. 



Irrigation is necessary on light soils in New Jersey, 

 2 inches every 10 days, either overhead or trickle. 



In New Jersey, most blueberries are grown with 

 clean cultivation. This practice helps to control 



mummy berry. Sod middles are good for pick-your- 

 own. 



Bees may be needed for pollination at the rate of 0.5 

 to 2 hives per acre, depending on cultivar. Some 

 cultivars are more attractive to bees and require fewer 

 hives per acre, while unattractive cultivars require 

 more. 



Iron deficiency can be a problem on soils with high 

 pH. It is advisable to test the pH every year. 



When it comes to fertilizer, the ammonium form of 

 nitrogen is preferred. Do not use fertilizers containing 

 potassium chloride (muriate of potash), since chlorine 

 is harmful to blueberries. 



Recommended planting distances in New Jersey 

 are 3.5 or 4 feet by 10 feet. On new plantings, do not 

 apply any fertilizer in the planting hole; wait until new 

 growth begins. 



On new bushes, remove fruit buds. In the second 

 year, prune twiggy growth, low horizontal branches, 

 and fruit buds. In the third year, you can leave some 

 fruit. In the fourth year, allow bushes to fruit if they 

 have made good growth. 



Incorrect pruning or lack of pruning is the main 

 cause of poor growth and low yields with blueberries. 

 As canes grow older, over 5 years, they become less 

 productive. In pruning, remove dead and diseased 

 canes. Then remove 1 of every 6 canes. Remove the 

 oldest canes and low, spreading canes. Cut at ground 

 level, do not leave stubs-stubs block new canes and are 

 a source of disease innoculum, such as Phomopsis. 

 Open up the center of the bush to allow sunlight to 

 penetrate. Wear gloves when pruning. Use both 

 hands, one to hold the primer and the other to knock off 

 twiggy growth. 



20 



Fruit Notes, Summer, 1990 



