Content
Many gardeners are faced with the fact that blueberry leaves turn red. And then the question arises whether such a phenomenon is considered the norm, or whether it serves as a sign of the onset of a disease. In fact, the causes of reddening of the leaves can be very diverse, this article will help you understand them in more detail and learn about methods for saving a plant.
Why do the leaves of garden blueberries turn red
To correctly diagnose the causes of reddening of blueberry leaves and choose the most effective treatment, on which the life of the plant may depend in some cases, is necessary. first of all, start from when and under what conditions this phenomenon began. Typically, blueberry leaves usually turn red in autumn and early spring when temperatures drop.
Why do blueberry leaves turn red in autumn
Do not worry only if blueberry leaves turn red in the autumn, since this is a natural phenomenon. In the fall, the plant begins preparing for winter, accompanied by the redistribution of nutrients. During this period, the color of blueberry leaves acquires a rich burgundy-red hue. Depending on the natural conditions of the region, the leaves usually begin to turn red in October or November.
Why do blueberry leaves turn red in spring or summer?
If blueberry leaves turn red in summer or spring, you should understand in more detail the reasons for this phenomenon. There may be several factors. In spring, blueberry foliage turns red, as a rule, during sudden cold snaps. The cause of reddening of the leaves in summer is most often such fungal diseases as phomopsis and stem cancer.
Why do blueberry leaves turn red after planting
The most common reason blueberry leaves turn red after planting is when the plant is placed in soil with the wrong acidity. Blueberries do not like too acidic soil, and on neutral soils, its foliage begins to turn red.
Why do blueberry leaves turn red and what to do
There are not many reasons why blueberry leaves can turn red in summer or spring. These include:
- Low air temperature;
- Low acidity of the soil;
- Lack of nutrients in the soil, and in particular a deficiency of magnesium and phosphorus;
- The defeat of fungal diseases, which can be asymptomatic for a long time, which is extremely dangerous, since this can lead to infection of neighboring plants;
- Root rot affecting blueberry bushes growing in damp areas. To prevent its development, it is recommended to transplant the plant into areas mulched with compost, pine bark or sand.
Low temperature
In early spring, when the stable warm weather has not yet settled, blueberry leaves often turn red due to sudden temperature fluctuations and nighttime cold snaps. Such a reaction is normal, you should not rush to make any manipulations with the plant, with the exception of preventive treatments for fungal diseases.You should watch the shrub for a couple of weeks, with warming, the color of the leaves should change to the usual green.
Low soil acidity
If, soon after planting healthy blueberry seedlings, the green leaf blades of the plant begin to turn red, the reason may be insufficient acidity of the soil. A characteristic sign of insufficient soil acidity is that the leaves, as a rule, turn red whole, and are not covered with individual spots.
The best option for blueberries, regardless of the variety, is considered a light soil with an acidity level of 3.5 - 4.5 pH. If the acidity of the soil is lower, the color of the leaves changes. To increase the acidity index, it is recommended to spill the soil with a special solution, which can be prepared by mixing citric or oxalic acid (1 tsp) with water (3 l). You can also acidify the soil with 9% acetic acid dissolved in water.
After such an event, several days must pass before the blueberry leaves return to their previous color. However, if after 10 - 12 days the foliage has not turned green, you should re-irrigate the soil with acidic solutions.
Phomopsis
Phomopsis is a fungal disease that can easily be confused with stem cancer. Phomopsis causes drying and twisting of the tops of young shoots. The main cause of the disease is waterlogging of the soil. Phomopsis viticola most often infects bushes growing in areas with high groundwater levels or in regions with high air humidity.
Through the tissues of the tops of young shoots, the fungus rapidly spreads to their bases, as a result of which the greens turn red and wither. The disease begins to manifest itself in June. Its first signs are small dark red, almost black, round or oval dots that form on the leaves. If the disease is left untreated, perennial old branches soon become infected.
If signs of disease are found, all affected shoots and leaves from the blueberry bush must be cut and then burned. The bush itself needs to be treated with fungicides. For this purpose, you can use drugs such as Topsin, Fundazol, Euparen. Spraying is carried out three times: twice before flowering (with an interval of a week) and once after picking berries.
Stem cancer
Another reason that the leaves turn red on blueberries may be an extremely dangerous fungal disease - stem cancer. When the stem cancer infects blueberry bushes, the area of leaf scarring is first covered with small red spots, which subsequently grow and acquire a brown color. Over time, the spots grow together with each other, then they begin to gradually spread over the surface of the shoots, causing them to die off. On lignified shoots, as a result, spots form expanding sores, at the place of appearance of which the bark peels off strongly.
With the development of stem cancer, blueberry leaves turn red long before the onset of autumn. The cause of the disease is most often the improper care of the plant: waterlogging of the soil, exceeding the rate of application of nitrogenous fertilizers.
It is almost impossible to get rid of stem cancer. To protect blueberry bushes from this dangerous ailment, it is recommended, first of all, to avoid planting plants in areas with high soil moisture and high groundwater levels.
For prevention purposes, blueberries are regularly sprayed with 3% Bordeaux liquid.The procedure should be carried out twice a year: in early spring - before the leaves bloom, or in late autumn - after they have already fallen off.
Also during the growing season, blueberry bushes must be sprayed with fungicides. Means such as Fundazol, Euparen, Topsin have proven themselves well. Fungicide treatment is carried out three times before flowering and three times after harvest. The interval between spraying should be about a week.
Prevention measures
The choice of blueberry seedlings should be approached responsibly, their appearance should be healthy, it is better to give preference to varieties that are resistant to fungal diseases.
The main preventive measures:
- Compliance with planting rules: preliminary fertilization, control of the degree of soil moisture, planting seedlings in sunny areas at a distance of at least 2 m from each other.
- Regular inspection of the bush, during which thickened, as well as dry and diseased shoots are removed. By pruning the bush, air circulation is improved, which prevents the development of many fungal diseases.
- Preventive treatment with Bordeaux liquid twice a season.
- Preventive fungicide treatments before flowering and after harvest.
- Timely collection and burning of fallen leaves.
Conclusion
Do not panic if blueberry leaves turn red, not always a change in pigmentation indicates the development of a disease. One of the most common causes of this problem is improper plant care: too acidic soil, early planting, watering with cold water. Another common cause is fungal diseases, with timely treatment of which it is often still possible to save blueberry bushes.
