What says summer better than a bowl of perfect, round, blue fruits sitting on the tabletop or counter? Blueberries are one of the most rewarding plants one can plant in the garden, because they offer so much – multi-seasonal interest, habitat and food for all sorts of insects and animals, and a sweet treat for the gardener in the summertime. There are low-growing and dwarf cultivars as well, so even the smallest of gardens has room for a plant or two.
Vaccinium is a medium-sized genus of plants, many of which bear edible fruits. They require acidic soils, and can vary in size and form from very short ground covers to taller shrubs, reaching 6 or 7 feet. There are several species that are native to Maine, among them the Lowbush Blueberry (Vaccinium angustifolium), Highbush Blueberry (V. corymbosum), and the Mountain Cranberry or Cowberry (V. vitis-idaea). Most species have beautiful fall foliage, ranging in colors from orange and red to nearly purple. A blueberry barren in the fall is one of the most stunning sights of New England. They are rarely bothered by animal or insect pests or diseases, but birds do delight in the sweet fruits almost as much as we do. Netting is an effective way of protecting the crop. A sunny spot with rich organic soil and a good layer of mulch on top to keep moisture and temperature regulated is ideal for blueberries. Heavy fertilizer is not necessary, and over-fertilization can lead to excessive growth and higher potential for winter injury.
Lowbush blueberries are the essential “Maine Blueberry”. They are small, tartly sweet, and require very little care. They will quickly naturalize if they are in a moist but well drained, peaty, acidic soil, and will often times be the only species covering a wide area. The plant itself is fire-tolerant, which has been used as a tool in cultivation for many years. Commercial growers will often burn the blueberry fields every couple of years to get rid of any invading shrubs and weeds, and return nutrients such as potassium to the soil. In the home garden, it serves as a sweet little border plant, and is essential in erosion control. A couple plants will provide enough berries to enjoy on cereal, or to make a round of muffins, if they even make it inside the house!
Highbush blueberries are a medium sized shrub, and grow best in more open areas with moist, acidic soil. Commercially available varieties reach between 4 and 6 feet high and wide, and produce large, sweet berries. The shrubs themselves have exfoliating bark, which makes a nice display in the wintertime, and can be used as a deciduous hedge. The fruitset on most varieties of highbush blueberry is quite heavy, and a couple of mature plants will ensure that the sweet blue fruits can be enjoyed all summer and into fall, maybe even with enough for freezing for later. ‘Jersey’, ‘Rubel’, and ‘Patriot’ are among the best varieties, but there are many, many to choose from.
There are also hybrids, known as half-high blueberries, or dwarf highbush, that reach between a foot and three feet high. ‘Northsky’, ‘Northcountry’, and ‘Top Hat’ are some varieties that are perfect for the small garden. These combine the large fruits of the highbush blueberry with the small stature of the lowbush.
Like many fruits, blueberries do best when there are multiple varieties planted in the same area. Cross-pollination is not always required to get fruitset in blueberries, but the quantity and quality will definitely improve if you have it. Using two or more varieties that ripen at different times will also lengthen the harvest season.