The northern highbush blueberry (Vaccinium corymbosum) is a North American species of blueberry. The plant is found in wooded or open habitats with moist acidic soils. It forms a deciduous shrub growing to 1.5–2 metres tall. The dark green glossy leaves are elliptical and up to 5 cm long. In autumn, the leaves turn to a brilliant red, orange, yellow or purple. The flowers are long bell- or urn-shaped white to light pink. The species is tetraploid and does not self-pollinate. To produce fruit, it is necessary to plant several varieties (at least two) to ensure cross-pollination. The fruit is a blue-black berry with a 6.5–13 mm in diameter. The fruits ripen from early July to late September, depending on the variety. With optimal care, a harvest of 4–6 kg/bush can be achieved. Choosing the right location is very important for successful cultivation. An unsuitable location is the most common cause of problems during cultivation.
Specific soil requirements
Blueberries require light, well-drained sandy-loam soil rich in organic matter. In addition, they require strongly acidic soil with a pH between pH 3.5 and 4.5. The soil must not dry out, but it must not be too waterlogged either. If you have already planted blueberries, you can adjust the high pH by regularly using fertilizers in sulfate form (physiologically acidic fertilizers), adding peat, composted bark or composted sawdust from coniferous trees.
Location and planting
For maximum production, full sunlight throughout the day is essential. Blueberries are usually planted at a distance of at least 1.5 meters from each other in rows 2.4 to 3 meters apart. The plants are planted in pits that are filled with a suitable substrate. Do not add fertilizer to the pit. We need 40 liters of acidic substrate per plant. If the surrounding soil contains too much calcium carbonate, then separate the acidic substrate from the surroundings with plastic film. Water the plants thoroughly after planting. Make sure that the roots of the blueberries do not dry out during transplanting. Remove weak and broken branches.
Irrigation requirements and plant care
In our conditions, blueberries are fully frost-resistant; during the dormant period, they can withstand temperatures down to -29 °C. Water is one of the limiting factors in the successful cultivation of blueberries. Especially after planting and in the first year of cultivation, they are extremely sensitive to water shortages. They have the greatest moisture requirements during the period of intensive berry growth and flower bud differentiation, i.e. from May to September. Due to the permeable growing substrate in which they are grown, we irrigate the plants evenly and sufficiently from flowering to harvest as needed and control perennial and annual weeds. Blueberries have a shallow root system and should be mulched with a 7 to 10 cm layer of organic mulch. Good mulches include wood chips, bark, pine needles, leaves, or a combination of these. Moisten the soil before applying the mulch.
Choosing the right fertilizer
Blueberries prefer acidic soil and need nitrogen in the ammonium form, not nitrate. Avoid over-fertilizing, especially with new plants, and consider using a slow-release, granular fertilizer. Blueberries utilize ammonium (NH4+) nitrogen best, so choose fertilizers like urea, ammonium sulfate, or a balanced fertilizer specifically formulated for acid-loving plants. Avoid fertilizers containing only nitrate (NO3-) as they can be harmful to blueberry plants. Fertilizers designed for azaleas, camellias, and rhododendrons are often suitable for blueberries. In the first year, apply fertilizer about a month after planting, spreading it evenly around the plant. Repeat this application in 4-6 weeks. For young plants, the dose is 30 g, for mature plants 100-150 g of ammonium sulfate per year. For mature plants, fertilize in early spring when new growth begins. Apply a second application about six weeks later to support fruiting. Do not apply fertilizers after July 1, to avoid stimulating late season growth.
Prunning
Blueberries do not suffer from significant diseases and are resistant to pests. Pruning during the first 4 years of cultivation is only the removal of weak, diseased and dead shoots. Do not perform a lightening and rejuvenation pruning of the bushes until the 5th year. Cut out the oldest shoots that do not have young fruit-bearing annual shoots. The most suitable time for pruning is at the end of winter.
Healing effects of blueberries
The unusually high content of antioxidants (including vitamin C) in blueberries helps to build a protective shield in our body against free radicals, viruses and bacteria. Blueberries are therefore a great prevention of many diseases, a medicine and a strong support during convalescence, they protect our mucous membranes and stimulate their regeneration. Fresh, dried, frozen or otherwise preserved blueberries are the right medicine for all respiratory diseases, they help treat flu, sore throat, bronchitis, colds and other infectious and inflammatory diseases of the mucous membranes. Another amazing effect is the ability to improve and maintain our eyesight, which has also been proven by professional scientific research. Their frequent consumption is an effective prevention of night blindness. People who have problems with night vision notice an improvement in vision in poor lighting conditions. Blueberries have been used for many generations as a remedy for intestinal problems and colic, diarrhea and food poisoning. Here they function as a disinfectant. They also have a beneficial effect on the kidneys and urinary tract, cleaning them and helping to treat any infections in this area. They have a mild diuretic effect, rid the body of harmful substances and improve the function of the lymphatic system. They also have a healing effect on the prostate, they are even spoken of as a natural prevention of prostate cancer, but also in connection with the prevention of many other types of cancer.
