What are the geographical conditions, benefits, and contraindications for growing cherries?

“The king of anemia” cherries have a high iron content, with as much as 59 mg of iron per 100 grams of cherries, ranking first among fruits. Their vitamin A content is 4-5 times more than that of grapes, apples, and oranges. Their carotene content is 4-5 times more than that of grapes, apples, and oranges. In the price of cherries, several hundred yuan per jin is very common, so what are the benefits and contraindications of cherries? What growing conditions are required?

I. Growing conditions for cherries

1. Temperature

Cherries are deciduous fruit trees that prefer warmth and cannot tolerate cold. Chinese cherries (Prunus pseudocerasus) originated in China's Yangtze River basin and adapt to warm, humid climates, with relatively weak cold resistance, so they are mostly cultivated in the Yangtze River basin and in northern areas with relatively warm microclimates. Sweet cherries and sour cherries originated in West Asia and Europe and adapt to relatively cool, dry climates, and are more suitable for cultivation in North China, Northwest China, and southern Northeast China. However, high temperatures and dryness in summer are unfavorable for sweet cherry growth. The minimum winter temperature must not fall below -20; excessively low temperatures can cause vertical cracking of large branches and gummosis. In addition, flower buds are susceptible to frost damage. If the temperature drops below -3°C during the flowering period, the flowers will suffer frost damage, so when developing cherries, overly cold areas are unsuitable.

2. Water

Cherries are very sensitive to water conditions; they are neither drought-resistant nor waterlogging-tolerant. In Chinese cherry cultivation areas, apart from southern provinces with abundant rainfall, northern regions mostly choose hillside and valley areas with relatively humid microclimates for cultivation. Looking at the distribution of sweet cherry cultivation areas around the world, most are chosen near river systems or coastal areas. China's main sweet cherry cultivation areas are currently mostly distributed in Bohai Bay areas such as Yantai, Shandong, and Dalian, Liaoning. These two places are near the sea, with annual rainfall of 600-900 mm, and the air is relatively humid. Cherries, like other stone fruits, require relatively high oxygen in the root system. If there is too much soil moisture and insufficient oxygen, it will affect normal root respiration, and the tree cannot grow and develop normally, causing root rot and gummosis, and in severe cases leading to tree death. If there is heavy rain and drainage is not timely, and the cherry tree is submerged in water for 2 days, the leaves will wilt but not fall off; the leaf wilting cannot recover and may even cause the entire tree to die.

3. Light

Cherries are a light-loving tree species, especially sweet cherries, followed by sour cherries and downy cherries; Chinese cherries are relatively shade-tolerant. When light conditions are good, the tree is robust, fruit branches live longer, flower buds are plump, fruit set rate is high, fruit ripens early, coloring is good, sugar content is high, and acidity is low. When light conditions are poor, the tree tends to grow excessively, branches inside the canopy weaken, fruiting branches have shorter lifespans, fruiting positions move outward, flower buds develop poorly, fruit set rate is low, fruit coloring is poor, ripening is delayed, and quality is poor. Therefore, when establishing an orchard, choose sunny slopes or semi-sunny slopes, planting density should not be too high, branches should be spread at an angle, and light conditions inside the canopy should be ensured to achieve ventilation and light penetration.

4. Soil

Sweet cherries are suitable for cultivation in sandy loam or gravelly loam with deep soil layers, loose texture, good aeration, and strong water retention. When cultivated in heavy clay soil, the root system is shallow, not drought-resistant, not waterlogging-tolerant, and not wind-resistant. Cherry trees are very sensitive to salinity. The suitable soil pH is 5.6-7, so cherry trees should not be planted in saline-alkali areas.

Cherries are very prone to crown gall disease. If there are crown gall bacteria and nematodes in the soil, crown gall disease is easily transmitted. In old orchards where cherries, peaches, plums, and apricots have been planted, there are many crown gall bacteria in the soil, so it is unsuitable to plant cherry trees there, and even more unsuitable to use them as nurseries for developing cherries. If the saplings have crown gall disease, it will cause even more serious consequences.

5. Wind

Cherry root systems are generally relatively shallow and have poor wind resistance. Strong winds in severe winter and early spring easily cause branch desiccation and flower bud freezing; strong winds during the flowering period easily dry the stigma mucus, affecting insect pollination; typhoons in summer and autumn can cause branch breakage and tree toppling, causing even greater losses. Therefore, in areas invaded by strong winds, windbreak forests must be established, or areas with good microenvironments should be chosen for orchard establishment.

II. Growing environment for cherries

Chinese cherries have weak cold resistance and prefer warm, moist climates, and are suitable for cultivation in places with an average annual temperature of 15-16°C. Sweet cherries prefer cool, dry conditions. The natural dormancy period of cherries is about 80-100 days. The chilling requirement for sweet cherries to complete dormancy is 1100-1300 hours below 7.2°C. Sour cherries require 1200-2500 hours. Chinese cherries have a relatively short dormancy period and easily sprout when temperatures warm up in late winter and early spring. If they encounter a “late spring cold snap” (frost or snow), the flower organs will be frozen, which can seriously affect yield, or even result in total crop failure. Therefore, when developing them, attention must be paid to whether the timing of local low-temperature cold waves each spring coincides with the flowering period. Places where unfavorable weather (frost, snow, strong winds) occurs during the cherry flowering period year after year cannot be planted. Even in places where disastrous weather rarely occurs, suitable micro-topography should be selected for planting when establishing an orchard.

The suitable annual rainfall for cherry growth is generally 700-1000 mm. In some southern areas, how to solve the “spring drought” problem should be fully considered when establishing an orchard. This is because drought in the early stage of fruit growth will cause serious fruit drop and affect fruit growth and development.

Cherries are a light-loving tree species. Chinese cherries are relatively shade-tolerant, but with good light, the fruit ripens early and colors well.

Cherries are suitable for cultivation in fertile, loose sandy soil with deep soil layers. Soil pH is generally 6.0-7.5.

The vertical distribution of Chinese cherry roots is generally concentrated in soil layers about 20 cm deep, requiring loose soil and good drainage and irrigation conditions. Heavy clay is not suitable for growing cherries. Since cherries do not tolerate transport, orchards should be established in locations with convenient transportation.

Planting density should vary according to variety, rootstock, and soil conditions. On fertile flat land, Chinese cherries can be trained in a Y-shape for dense planting at 1×3 m, with 220 trees per mu; if using natural clump form or natural open-center form, 2-3 m × 3-4 m can be used. In the juvenile period, density can be appropriately increased, and after the orchard is established, thinning measures can be taken.

Planting time is generally divided into two periods: autumn and spring. In areas with cold, dry, and windy winters, spring planting is preferable, and spring planting should be done before the saplings bud. In warm winter areas, autumn planting can be done. Before planting, the soil should be deeply plowed and matured, and large planting holes should be dug. Apply 25-50 kg of organic fertilizer per hole. After mixing the fertilizer with the soil, plant the sapling and immediately water to settle the roots.

III. Cherry growing techniques

1. Cultivation and soil use

Large cherries are suitable for cultivation in loose, fertile sandy loam with good permeability.

2. Soil, fertilizer, and water management

Water and fertilizer management: The water content of large cherry plants is about 70%, so they are particularly sensitive to water demand. Under normal circumstances, when there are many branches and leaves and temperatures are high, water frequently; otherwise, overly dry orchard soil will affect their growth and flowering and fruiting. The principle of applying thin fertilizer frequently should be followed. It is recommended to spray New High Lipid Film to enhance fertilizer efficiency utilization.

For cherry soil management, based on our experimental observations, the management method of spring irrigation plus mulching, and intertillage and weeding in other seasons, is better. Because mulching reduces the impact of spring drought on the plants, it has a good effect on fruit growth. After cherries are harvested, remove or plow under the mulch. According to calculations, a general mature orchard should be mulched with 2000-2500 kg of wheat straw per mu. Cherry trees should be fertilized 3-4 times a year, namely:

① Fertilization after fruit harvest: mainly to restore tree vigor, promote flower bud differentiation, and increase next year's yield. Immediately after harvest, apply barnyard manure and poultry/livestock manure and urine, and add an appropriate amount of chemical fertilizer. Apply 30-60 kg of poultry/livestock manure per tree depending on the amount of fruit set.

② Fertilization before budding and flowering: apply a topdressing mainly of quick-acting nitrogen fertilizer. Apply 15-20 kg of poultry/livestock manure water per tree, or 0.5 kg of urea.

③ Fertilization during the rapid fruit growth period: after petal fall, the fruit enters development. For large fruiting trees, apply one topdressing of quick-acting chemical fertilizer, together with an appropriate amount of phosphorus and potassium fertilizer.

④ Apply base fertilizer well: in autumn from September to October (in warm southern areas, October to November), apply base fertilizer before leaf fall to restore tree vigor and increase the stored nutrient content in the plant. Since cherries take only more than 40 days from flowering to fruit maturity, the amount of stored nutrients largely affects fruit size and quality. Therefore, the application of base fertilizer is very important and should account for 50-70% of the annual fertilization amount. It should be mainly organic fertilizer, such as compost, pen manure, chicken manure, decomposed soybean cake, etc., and an appropriate amount of superphosphate or calcium-magnesium phosphate fertilizer should be added.

In addition to the above soil fertilization, from the initial flowering stage to the full flowering stage, at an interval of 10 days, spray twice continuously with 0.5% urea, or 600 times potassium dihydrogen phosphate solution, or 0.3% borax solution, which helps increase the fruit set rate.

IV. Precautions for cherry planting

1. A place with relatively good sunlight exposure.

2. A place with good drainage; water must not accumulate for long periods.

3. Sandy soil and humus soil are suitable; do not plant in clay.

4. 2-3 days after new planting, water once to settle the root system.

V. Benefits and contraindications of cherries

1. Cherries can enrich the blood

Enriching the blood is one of the important benefits of cherries. They contain a large amount of the trace element iron, which can promote the regeneration of red blood cells, improve the human body's blood-producing capacity, effectively relieve anemia, and also reduce the occurrence of anemia symptoms.

2. Cherries can beautify

Beautifying is also one of the important benefits of cherries. They contain multiple vitamins as well as some sugars and amino acids. These substances act directly on human skin cells, can promote skin cell metabolism, nourish the skin, and also make the skin delicate, reducing the formation of wrinkles and age spots.

3. Contraindications for eating cherries

Although this fruit has remarkable benefits, it is warm in nature, and eating it will cause internal heat in the body. Therefore, people who already have a heat-prone constitution should not eat cherries, otherwise various symptoms of excessive internal heat will appear. In addition, cherries contain a large amount of sugar, and people with high blood sugar and diabetes also cannot eat cherries, otherwise the condition will worsen.