Blueberries can be challenging to grow in the warmer parts of the United States. Successful fruit production depends on a sufficient amount of winter cold, also known as “chill hours.” Northern states usually have between 600 and 800 chill hours, or more. Many blueberry varieties require at least 400 chill hours, which makes them unsuitable for much of the deep South. New cultivars have been developed that will bear an abundance of fruit in warm areas.
‘Sunshine Blue’ is an unusual selection, in that it is evergreen.This blueberry grows around four feet tall, with lush green foliage and an early spring bonus of bright pink flowers. The fruit is produced over a long season, extending the time for fresh harvests. Yields are usually quite heavy. Chill hour requirements are very low, only one hundred and fifty hours.
‘Misty’ is another evergreen, with leaf tips blushed slightly in red.Chill hours are the same as ‘Sunshine Blue.’ Both varieties are fantastic edible and ornamental plants, fitting easily into the landscape as an attractive filler shrub.
‘Sharpblue’ is probably the most widely adapted variety, growing anywhere in the US with five hundred chill hours or less. Although deciduous in most areas, in warm climates it will remain evergreen. Berry production is heavy.
‘Reveille’ is slightly larger than most other blueberries, growing to five feet tall. The growth pattern is more columnar, allowing more plants to be grown in a smaller area. Pink flowers in spring are followed by very tasty dark blue fruit.
Most blueberries require acidic, well drained soil. All of the varieties noted above can tolerate less acid, but a yearly mulch of conifer needles or bark is helpful. Regular summer moisture is crucial to fruit development. Blueberries have a very fine, shallow root system and do not like drought. Two different varieties should be grown for optimal pollination, but large blocks of the same type will do just fine. If growing only one variety, a quantity of ten to twenty is a good number for pollination. Although blueberries will tolerate soggy winter soil, overall plant health and fruit harvests improve greatly when planted in well drained soil. In places with heavy clay, plant in a raised bed or an a berm, making sure the soil is rich in organic matter and mulched with conifer needles or bark. A high acid mulch will also discourage weeds. Fertilizer is usually not necessary, and blueberries in general seem to do better without it. High quality compost and acid soil is all that is needed to keep them producing for many years to come.
Japanese beetles can occasionally be a pest, feeding on leaves and fruit. Commercially sold traps will keep populations in check, as will handpicking. Regular harvesting of the fruit will also help, as over ripe berries seem to attract them. Aphids can attack the tender new growth, but can be easily knocked off the plant with a strong spray of water.
Disease problems are rare, and usually caused by poorly drained soil and over fertilizing. Healthy soil and minimal fertilizer will keep plants healthy. A disease called ‘Mummy Berry’ is the most common problem. The berries afflicted wither away at their peak of ripeness. This diseases spreads by spores, and can be controlled with good sanitation. Simply remove all fallen leaves, left over fruit, and dead branches at the end of the season.
