We’re excited to introduce this new bimonthly column in Growing focusing on berries, bush fruits and other small fruits. The column will alternate with the existing Organics column to provide an even wider range of information for you. Let us know what you think; drop us a note at GrowingLetters@MooseRiverMedia.com or stop over to FarmingForumSite.com and post in the Fruits section!
Blueberries are members of the Ericaceae family of plants, which includes many familiar shrubs like rhododendrons, azaleas and heathers. These plants share a fondness for acidic soils and, probably as a result, most have fungi associated with their roots to help with the uptake of nutrients. Within this family is the genus Vaccinium, which includes cranberries and blueberries, both native to North America.
Many kinds of blueberries
The highbush blueberry (Vaccinium corymbosum) is the most widely cultivated species of blueberry, and it’s grown in California, Oregon and Washington across the Upper Midwest and over to the Northeast and mid-Atlantic states. Michigan produces about a third of all the U.S. highbush blueberries; New Jersey produces about one-fifth of the annual crop.
The lowbush, or wild blueberry (V. angustifolium), is adapted to colder climates and the bulk of the commercial crop is produced in Maine, with a little coming from other parts of northern New England, Michigan and Wisconsin. Rabbiteye (V. ashei) is a large blueberry bush that’s adapted to production in the South.
Americans eat on average just under a pound of blueberries a year—half frozen, half fresh. The consumption of frozen blueberries has been trending downward, while fresh berry consumption is on the rise.
Better than a pill
One thing all blueberries have in common is their health benefits. Researchers have found blueberries to be high in antioxidants. By combating free radicals in our bodies, antioxidants help protect against cancer and delay the aging process. There’s also evidence that blueberries can reduce urinary tract infections, protect against heart disease and improve night vision.
Native Americans knew that blueberries were good for treating stomach problems, but they were limited to eating wild blueberries. They produce fruit that’s quite small, but suited to plants that only grow about a foot tall. The domesticated, or highbush blueberry, produces bigger berries, and more of them on a plant that grows nearly 10 times taller than its wild cousin.
Not so long ago
The domestication of the blueberry started in 1908 when Dr. F.V. Coville, a researcher at the U.S. Department of Agriculture, began studying wild blueberries and seeking out superior plants for breeding. He made his first selection of plants in New Hampshire. In 1911, Elizabeth White, a commercial cranberry grower in New Jersey, learned of his work and offered her assistance. For the next two decades she enlisted her pickers to search for exceptionally fine bushes in the wilds of New Jersey’s pine barrens.
Coville made crosses among the best of these plants, and the highbush blueberry industry was born. He developed the first 15 commercial varieties of blueberries, and many more followed as a result of his work.
In 1937, a Vermonter took over the USDA blueberry breeding program. Dr. George Darrow initiated cooperation with state agricultural experiment stations and private growers, so that new varieties could be tested in widely different growing areas. Between 1946 and 1962, he provided over 200,000 seedling plants to cooperators in 13 states. One of these cooperators was his brother, Bill, who ran Green Mountain Orchards in Putney.
The first highbush blueberries in Vermont were planted in 1948. “Several years ago,” Bill Darrow Jr. told me, “Dad put in 30 or 40 bushes at first. By 1950, he was growing four varieties. He tried different ways of feeding them, and lost quite a few in the process. Eventually, he got things squared away, so we cleared the pines off Round Hill, hauled in sawdust from the mill, and planted a couple of acres. We started in 1952, but it took three years to get enough seedlings to finish the planting.”
Today, highbush blueberries are grown up and down the state, and in 37 other states as well. In 2007, the farmgate value of blueberries in the United States was almost $600 million. Many varieties have been developed over the years, with new ones steadily coming along. In the coldest locations, “half-high” varieties that have both lowbush and highbush parentage make sense. They are better able to tolerate cold winter conditions than pure highbush types, but they are bigger and yield more fruit than do lowbush plants.
Varieties currently recommended for the cold climates of northern Michigan, New York and New England (zone 3 or 4) include those with sufficient winter hardiness: Blueray, Bluetta, Jersey, Northland and Patriot, and the half-high varieties Northblue and Chippewa.
In slightly warmer areas like southern Michigan and southern New England and New York (zone 5 or 6), consider Berkeley, Bluecrop, Bluejay, Blueray, Duke, Elliott, Lateblue, Jersey, Nelson, Patriot, Rubel, Spartan and Toro.
Soil is central
According to Dr. Gary Pavlis of Rutgers University, the three keys to success with blueberries are: pH, pH and pH. So, always test the soil before planting and adjust soil pH if necessary. A soil pH of 4.5 to 5.5 is optimum for blueberry production; at a pH above 5.8 you may see signs of iron deficiency when the leaves start to yellow in between the veins. The soil pH can be lowered by adding elemental sulfur and mixing it in the year before planting to allow time for it to react. Your soil test results should give you a recommendation for how much sulfur to add, as well as any fertilizer nutrients.
Sandy soils with a high organic matter content are best for providing the aeration that blueberries need, but loamy soils can be suited to this crop, too. To improve plant establishment on most soils, make a wide, shallow planting hole and mix in 1 to 2 cubic feet of peat per plant. Avoid planting blueberries in soils with poor aeration and drainage, as this usually leads to poor growth and root problems. Once your crop is growing, leaf analysis is the best way to determine how much, and what type, of fertilizer they require.
Blueberries live a long time. Be sure to leave them plenty of space to grow after you plant them. A wide row spacing of 10 or 12 feet or more will allow easy access with equipment between mature plants. It will also provide for good air movement. However, it can increase the cost of netting to protect against birds, since there will be more area to cover. Keep a water supply in mind, since drip irrigation can increase yields in many years.
For detailed information on growing this crop, visit the Michigan State University blueberry Web site, www.blueberries.msu.edu. You can also check out the 200-page Highbush Blueberry Production Guide from www.nraes.org, or call 607-255-7654.
The author is vegetable and berry specialist with University of Vermont Extension based at the Brattleboro office, as well as a longtime contributor and columnist for Growing.