Content
Many gardeners are faced with blueberry leaves turning red. And then the question arises whether such a phenomenon is considered normal, or whether it serves as a sign of the onset of a disease. In fact, the reasons for the redness of leaves can be very diverse; this article will help you understand them in more detail and learn about methods for saving the plant.
Why do blueberry leaves turn red?
It is necessary to correctly diagnose the causes of redness of blueberry leaves and select the most effective treatment, on which in some cases the life of the plant may depend. First of all, start from when and under what conditions this phenomenon began. As a rule, blueberry leaves tend to turn red in the fall and early spring when temperatures drop sharply.
Why do blueberry leaves turn red in the fall?
You should not worry only if the blueberry leaves turn red in the autumn, since this is a natural natural phenomenon.In autumn, the plant begins preparation 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, usually during sudden cold snaps. The cause of reddening of leaves in summer is most often caused by fungal diseases such as Phomopsis and stem cancer.
Why do blueberry leaves turn red after planting?
The most common reason that blueberry leaves turn red after planting is placing the plant in soil with incorrectly selected acidity. Blueberries do not like too acidic soil, and on neutral soils their foliage begins to turn red.
Why do blueberry leaves turn red and what to do?
There are not many reasons why blueberry leaves may turn red in summer or spring. These include:
- Low air temperature;
- Low soil acidity;
- Lack of nutrients in the soil, and in particular deficiency of magnesium and phosphorus;
- Infection with fungal diseases that can remain asymptomatic for a long time, which is extremely dangerous, since this can lead to infection of neighboring plants;
- Root rot that affects blueberry bushes growing in damp areas.To prevent its development, it is recommended to replant the plant in areas mulched with compost, pine bark or sand.
Low temperature
At the beginning of spring, when consistently warm weather has not yet established, blueberry leaves often turn red due to sudden temperature fluctuations and night cold snaps. This reaction is normal; there is no need to rush to perform any manipulations with the plant, with the exception of preventive treatments against fungal diseases. You should observe the bush 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 cause may be insufficient acidity of the soil. A characteristic sign of insufficient soil acidity is that the leaves, as a rule, turn red entirely, rather than being covered with individual spots.
The best option for blueberries, regardless of the variety, is 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 will change. To increase the acidity level, 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 acquire their previous color. However, if after 10 - 12 days the foliage has not turned green, the soil should be re-watered with acidic solutions.
Phomopsis
Phomopsis is a fungal disease that can easily be confused with stem cancer. Phomopsis causes drying and curling of the tops of young shoots. The main cause of the disease is waterlogging of the soil. The fungus Phomopsis viticola most often affects 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 greenery turns red and withers. The disease begins to appear in June. Its first signs are small dark red, almost black, round or oval dots that form on the leaves. If the disease is not treated, perennial old branches will soon become infected.
If signs of the disease are detected, all affected shoots and leaves from the blueberry bush must be cut off 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 the berries.
Stem cancer
Another reason why blueberry leaves turn red may be an extremely dangerous fungal disease - stem cancer. When stem canker attacks blueberry bushes, the leaf scar zone first becomes covered with small red spots, which subsequently grow and become brown in color.Over time, the spots grow together, then they begin to gradually spread over the surface of the shoots, causing them to die. On lignified shoots, the spots eventually form expanding ulcers, at the site of which the bark peels off heavily.
When stem cancer develops, blueberry leaves turn red long before autumn. The cause of the disease is most often improper care of the plant: waterlogging of the soil, exceeding the norm for applying nitrogen fertilizers.
It is almost impossible to get rid of stem cancer. To protect blueberry bushes from this dangerous disease, it is recommended, first of all, to avoid planting the plant in areas with high soil moisture and high groundwater levels.
For preventative purposes, blueberries are regularly sprayed with 3% Bordeaux mixture. 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.
Also during the growing season, blueberry bushes must be sprayed with fungicides. Such products as Fundazol, Euparen, Topsin have proven themselves well. Fungicide treatments are carried out three times before flowering and three times after harvesting. 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; preference should be given to varieties that are resistant to fungal diseases.
Basic preventive measures:
- Compliance with planting rules: preliminary application of fertilizers, monitoring 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 improves, which prevents the development of many fungal diseases.
- Preventive treatment with Bordeaux mixture twice per season.
- Preventive treatments with fungicides before flowering and after harvest.
- Timely collection and burning of fallen leaves.
Conclusion
Don’t panic if blueberry leaves turn red; a change in pigmentation does not always indicate 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.
