Wednesday, October 12, 2011

Blueberries

Can we grow blueberries here in Hawai`i? 
With all the talk recently about the health benefits of blueberries, I can understand why many people are wondering if they can grow blueberries here in the tropical, blue Pacific.  Most of us think about the cold Northwest where many blueberries are grown. Actually, there are three main types of blueberries grown throughout the continental United Sates: Rabbit-eyes, low-bush, and high-bush varieties.  Now, thanks to the University of Florida’s hybridization program, there are a number of new varieties that will grow well in warmer climates like Florida and California…. and  Hawaii.

California’s Agricultural Extension Service began researching blueberries in the 1990’s. Today California has over 6,000 acres, producing 14 million pounds of fruit, which is low compared to the 100 million pounds produced in Michigan.

Blueberries grow best in moist, well-drained, acid soils.  They also like humidity.  The bushes grow 6-8 feet tall and about 4 feet wide. They do best in a cooler climate, thus a higher elevation may be more conducive.  It is recommended to plant blueberries on raised beds that are 8 – 18 inches high and 3 - 4 feet wide to provide additional drainage and aeration. After planting, apply mulch such as woodchips or other organic material. Mulch helps to keep the soil cool and conserve moisture. It adds organic matter and controls weeds. 
Blueberries are free standing and require no trellis.  They have a shallow, fibrous root system and are susceptible to drought.  Pruning is important. . Blueberries also do well in containers.

The three most common problems encountered are birds, Chinese rose beetles and a rust disease. The birds, waiting for the berries to ripen, can be deterred with netting.   The severity of the rust is reduced by growing plants under cover to keep the rain out. Promptly removing diseased leaves will also reduce disease pressure.   Fruit flies do not seem to be a problem yet.

Among the many varieties of blueberries there are six being evaluated at the Mealani Research Station located in Waimea at an elevation of 2800 feet above sea level: Biloxi, Emerald, Sharpblue, Sapphire, Jewel and Misty. Jewel and Misty gave the least yields. Sharpblue produced the sweetest fruit, but all were well received in informal taste tests. Some reports state blueberries are growing reasonably well at 1000 feet.   Plant a number of different varieties and see which ones perform the best for your particular area.
Some plants can be purchased from mainland nurseries in Oregon, Michigan and other states but may require a large quantity purchase.  

Ask the Garden Guy, Science Based Answers to Garden Questions, is an excellent resource book for gardeners. Some popular topics include Slugs and Snails, Organic Pesticides, Reasons, Why Vegetable Seeds Do Not Germinate, What’s So Hot about Manure? Mushrooms in the Lawn.  Purchase by clicking on the image of the book above.