The historical homeland of blueberries is North America. The distribution area of tall shrubs is river floodplains, wetlands. The wild species formed the basis for a large number of dessert varieties with good yields and a high gastronomic value. Blueberry Denis Blue is the result of New Zealand selection, the priority in the work was to create a variety adapted to cold climatic conditions. In Russia, the culture is grown throughout the European part of the country; in 2013, Denis Blue blueberries were entered in the State Register.
Description of blueberry variety Denise blue
Denis Blue blueberry is a perennial deciduous spherical shrub that grows up to 1.5 meters by the age of six. Frost-resistant culture safely withstands temperatures down to -40 0C, freezing of shoots is rare. The shrub is not afraid of a sharp change in temperature in the spring, since the flowering of blueberries is later, after possible return frosts.
Blueberries are grown in Siberia, in the Urals, in the Central lane and in the Moscow region for obtaining berries and as a design element in ornamental gardening. Denis Blue looks aesthetically pleasing from the moment of flowering to the autumn change in the color of the leaves. In September, the crown becomes bright yellow, then the leaves take on a burgundy hue, do not fall off until the onset of frost. Densely branched shrub, young shoots grow quickly and in huge numbers.
External description of the Denis Blue variety of garden blueberries:
- Stems are thin, upright, with slightly drooping tops, tough, flexible, completely stiff. The bark is smooth, light brown with a gray tint. A rounded shrub, growing in width, 1.3 m in diameter.
- Blueberry Denis Blue is densely leafy, leaf blade 3-3.5 cm long, obovate, lanceolate, opposite arrangement. The surface is smooth, with a mesh of veins, glossy, green. Cuttings are hard, medium volume, long, dark beige.
- Abundant flowering, flowers are light pink, small, water-lily, 6-10 pieces are formed on the fruit cluster.
The root system is poorly developed, it is close to the surface, the roots are thin, fibrous, they cannot independently provide Denis Blue with nutrients. The peculiarity of the culture is the way of obtaining the necessary microelements, it consists in symbiosis with the mycelium of the fungus. Mycorrhiza provides the vital activity of both the fungus and the plant.
Important! Fungi can exist only in an acidic environment, hence the requirement for the composition of the soil.
Features of fruiting
Blueberry variety Denis Blue belongs to the mid-season, the shrub blooms in June, berries are harvested in the second half of August. Ripening is uniform, clusters are located on the outer part of the stems, easily accessible for harvesting fruits. Denis Blue can give the first fruits in the third year of vegetation. Forms single flowers, they are not left on the bush, since the productivity of a young plant is low.
Full fruiting occurs in 5-6 years, the yield of the variety is high, 6-8 kg of berries are harvested from one bush. Blueberry is a dioecious plant, forms female and male flowers, cross pollination. The variety can do without pollinators, but in this case the yield drops. For a high fruiting rate, it is recommended to plant varieties with simultaneous flowering next to Denis Blue blueberries; Bluecrop, Northland blueberries are suitable as a pollinator.
Berries of the Denis Blue variety are of the same size, are colored at the stage of technical ripeness, but acquire the taste after 3 weeks. The fruits are not prone to shedding, are well fixed on the stalk, the separation is dry. They do not bake in the sun with sufficient watering. In case of moisture deficiency, they grow smaller, sour, loose, lose their shape.
Description of Denis Blue blueberry fruits (shown in the photo):
- shape in the form of a circle compressed on both sides, weight - 1.9 g, diameter - 18 mm;
- the peel is strong, elastic, thin;
- the blueberry berry is smooth, there is a small depression on top with a toothed receptacle;
- the color is dark blue with a silvery waxy coating, a ripe berry has a juicy pulp, dense structure, light purple.
The presence of acid in the taste is minimal, the berry of the variety is sweet, with a light aroma. They consume fresh blueberries, process them into juice, produce wine, prepare jam and jam. They do not lose their taste after freezing. Denis Blue variety is suitable for commercial cultivation, fruits are stored for about 7 days, transported in a refrigerator with a temperature not higher than +5 0C.
Advantages and disadvantages
According to gardeners, the Denise blue blueberry variety has a number of advantages:
- frost resistance;
- high yield;
- good taste;
- versatility in use;
- simple agricultural technology;
- duration of fruiting.
Important! The berries on the bush are preserved after the leaves fall, they do not lose their taste after the first frosts.
The disadvantages include low drought resistance, intensive formation of young shoots, the shrub requires pruning. Average resistance to infection.
Denis Blue blueberries reproduce only vegetatively:
- By cuttings. The material is harvested in the spring from last year's shoots. The cuttings are placed in a nutrient substrate at an angle of 450, watered, covered for the winter, planted next year in the fall.
- By dividing the bush. Work is carried out after fruiting; for division, a shrub is taken at least 4 years old.
- Layers. In the spring, before the sap flow, the lower branch is added in, the next spring plots are cut and planted on the site.
A prerequisite for independent reproduction is that the topsoil must not dry out.
Planting and caring for blueberries Denise blue
If the planting is carried out with self-grown material, the blueberries are disinfected with a 5% manganese solution, the root is lowered for 4 hours. Then apply any drug that stimulates growth, use in accordance with the instructions. If an acquired seedling is planted, it must be two years old without signs of mechanical and fungal infection.
Denis Blue blueberry is a frost-resistant representative of the species. Planting can be done in spring or fall. In the first case, the timing depends on the characteristics of the climate, the main condition is the heating of the soil to +8 0C. For the middle lane, the approximate time for spring planting is early or mid-May. Autumn planting is carried out 1 month before the onset of frost, blueberry survival rate is high, this time is enough for the plant for rooting.
Site selection and soil preparation
Blueberry variety Denis Blue does not tolerate even slight shading. Photosynthesis is completely dependent on the amount of ultraviolet radiation. In the shade, vegetation slows down, productivity decreases. A suitable area for blueberries is an open, well-ventilated area (the plant is not afraid of drafts). A wetland or lowland is suitable. The composition of the soil must be acidic. The site is dug up, a nutritious substrate is prepared from peat, sawdust, needles, sand.
A seedling with a closed root system purchased from the nursery is already supplied with mycelium. For self-grown material, mushroom spores are bought.
- Dig a hole with a diameter of 80 * 80 cm, a depth of 0.6 m.
- Pour ½ part of the mixture to the bottom, mushroom spores on top.
- Put the blueberries in the center, carefully spread the roots along the bottom, they should completely cover the area with mycelium.
- Fall asleep with the rest of the substrate and soil.
- They are tamped, watered, mulched with sawdust mixed with peat or pine needles.
If several blueberry bushes are planted in one line, the interval between them is 1.5 m.
Growing and care
Correctly carried out planting and adherence to care recommendations will provide Denis Blue blueberries with normal vegetation and high productivity. Agricultural technology includes: timely watering, feeding and maintaining the necessary acidity of the soil.
Denis Blue blueberry is a non-drought-resistant plant, so watering is required for the shrub. The roots are close to the surface, so the soil must be constantly moist. But excessive watering should not be allowed, excess moisture can provoke root decay.
Watering is carried out in the morning and in the evening every other day. The daily rate is 5 liters. The frequency of watering is increased in July, since this is the time when the berries are set. At low humidity, the bush is sprinkled, the procedure will accelerate photosynthesis and protect blueberries from overheating.
Denise blueberries are fed from the second year of growth. In the spring (before the leaves appear) with a nitrogen-containing agent, and at the time of berry formation - with universal complex fertilizers or a mixture of potassium sulfate (35 g), ammonium sulfate (85 g) and superphosphate (105 g). Fertilizers are applied under the bush in 1 tbsp. l. After two years, the amount is doubled, the maximum dosage is 8 tbsp. for adult blueberries.
Soil acidification is a mandatory procedure in agricultural technology. In a neutral or slightly acidic environment, fungi cannot exist, the death of one participant in symbiosis affects the viability of another. If blueberry leaves turn white with a yellow or pink tint, this is the first sign that the acidity of the soil is low. If the acidity level is unsatisfactory, it is increased by adding 1m2 one of the means:
- citric acid or oxalic acid - 5 g / 10 l;
- apple cider vinegar - 100 g / 10 l;
- colloidal sulfur - 1 ml / 1 l;
- electrolyte - 30 ml / 10 l;
Blueberries react negatively to organic fertilizers; they are not used for growing crops.
Attention! Do not feed with potassium chloride, because the product can cause the death of mushrooms and blueberries.
Pruning of the Denis Blue variety begins at the age of three. Shoots are shortened in spring by 1/3 of their length. The procedure is continued until the fruiting age. After 5 years, blueberries are cut in the fall, twisted branches are removed, the bush is thinned out. Frozen stems and dry areas are cut in the spring.
Preparing for winter
A frost-resistant plant after five years of growing season does not require crown cover. If the shoots are damaged by frost, blueberries quickly form a replacement without losing yield. In autumn, the bush is watered with a large volume of water and mulched with a layer of peat, wood chips or needles. In addition to mulch, young seedlings require crown cover. The branches are pulled into a bunch, fixed. Arches are placed near the blueberries, covering material is pulled.
Pests and diseases
For preventive purposes, along with sanitary pruning, Denis Blue blueberries are treated with fungicides. When a fungal infection appears, "Fitosporin" is used, watered with a solution of "Fundazol". Parasitizing on the bush: leafworm, flower beetle and beetle crustacean. They get rid of pests with Iskra, Inta-Vir, Fundazol.
Blueberry Denis Blue is a garden variety with a high yield, frost resistance and standard agricultural technology. A breeding crop created specifically for growing in cold climates. The shrub has a decorative look and edible berries, so the culture is grown as an element of landscape design and for harvesting.
Blueberry reviews Denis Blue
Ekaterina Zaitseva, 52 years old, Irkutsk
Blueberry variety Denis Blue in my country house for 6 years. Last year I collected 5 kg of berries. This season 1.5 kg less. The berries are tasty, sweet, juicy. I processed it into compote, cooked jam, froze some of it. The fruits ripened at the end of August, I left part of the harvest on the bush for the experiment. The berries did not fall to frost and completely retained their taste.
Raisa Ryumina, 32 years old, Moscow region
I have 5 berry bushes on the site planted along the fence, among them the Denis Blue variety. The fruits are large, juicy, without acid. The shrub looks aesthetically pleasing, flowers and leaves appear almost simultaneously. The plant blooms profusely, the bush is completely pink. Clusters of blue berries give decorativeness; in the fall, the crown becomes bright burgundy. The appointment turns out to be multifunctional, in addition to delicious fruits, the Denis Blue variety decorates the site with its appearance.