Blueberries – “the youth berries of the 21st century”
One of the newest non-traditional garden plants in Lithuania is the garden blueberry (Vaccinium x covilleanum Butkus et Pliszka), a long-lived garden cultivar that grows in acidic soils and produces for 25 40 years. It is a summer-green shrub with a height of 1.5-1.8 m, beautiful in all seasons.
The value of the berries. The berries are delicious, reddish-purple, blue in colour, depending on the variety, and ripen in the second half of July through September. It is the largest source of antioxidants among fresh fruit and vegetables, which does not diminish even if the berries are stored for a long time. The valuable properties of the berry have led to it being called the ‘youth berry of the 21st century’. The substances contained in the berries protect the body against ageing (atherosclerosis, Alzheimer’s, Parkinson’s disease as well as various forms of cancer), reduce cholesterol levels in the blood, have a positive effect on the heart and the cardiovascular system, reduce eye fatigue in computer users, and enhance eyesight. Blueberries never cause allergies and are suitable for consumption by people with diabetes.
Growing blueberries
Early and medium-late varieties of blueberries are grown in Lithuania.
Planting. Blueberries are light-loving plants and are best grown in open, wind-sheltered areas, in acidic raised bog peat or sandy loam soils (pH 4.0-4.5). Planted in early spring, late April/early May or in autumn.
To grow blueberries in heavy calcareous loam or clay soils, pits (1.5 m long, 1.5 m wide, 0.5 m deep) are dug. A layer of 5-10 cm of coarse sand or gravel is poured onto the bottom of the pit, then filled with a substrate specially prepared for blueberries, consisting of an acidic substrate (pH 4.0-4.5), a humus-rich, light raised bog peat, tree bark and a water-absorption promoter.
2-3-year-old seedlings are best. They are planted at the same depth as they grew before or a little deeper. In plantations, the planting of blueberries is done in rows, with a spacing of 1.0-1.2 m between the plants in the row and 3.0-3.5 m between the rows. After planting, the plants are watered and mulched with a layer of 5 to 10 cm of mulch. In the first year, all the flower buds are removed, in order to strengthen the root system.
Fertilising. The fertiliser is applied 3 times: at the end of April with a 0.1% solution (or 20 g/plant) of Nutricomplex (NPK 14:11:25), a complex fertiliser with trace elements; before flowering in mid-May and after flowering in June, with a 0.1% solution (or 20 g/plant) of ammonium sulphate, with a pH between 4.2 and 4.5. Spring-planted blueberries are given a first application of fertiliser that year, after they have settled in, after 3-4 weeks, and are then given a second application of 0.1 % ammonium sulphate in June. Watering is necessary during droughts. During the growing season, plants are watered 2-3 times with acidified water.
Mulching. Mulch should be a layer of 5-10 cm of sawdust, bark or acidic peat, but no thicker than this, to leave a gap of 3-5 cm near the stems of the berry bushes and to prevent damage to the sensitive bark. Do not mulch young, not fully rooted plants with fresh, dry sawdust or compost with a high pH > 6.5.
Pruning blueberry bushes. Young berry bushes are usually not pruned, and it is only after two years that branches bending toward the ground can be removed. After five years of growth, the first lightening can be done. Thereafter, regular pruning helps to regulate the growth and density of the bush, ensuring a consistent harvest of good-quality berries.
Pruning is done in early spring, in March, in sunny and dry weather.