When Is the Best Time to Plant Tea Plants? A Detailed Guide to Soil and Environmental Requirements
When is the best time to plant tea plants? Among the four seasons of the year, spring and autumn are both suitable for transplanting tea seedlings. Early spring (late February to early March) and late autumn (mid-October to November) are the best periods for transplanting. However, transplanting in late autumn and early winter is better than transplanting in spring, because in late autumn and early winter the above-ground growth of the tea plant has gradually entered the dormant period, while the underground root system is in an active growth period because the soil temperature is higher than the air temperature. Tea seedlings transplanted during this period benefit root growth and development. It is beneficial for the recovery and regeneration of roots injured during seedling lifting, and beneficial for the survival of tea seedlings.
What requirements do tea plants have for the soil they are planted in? Tea plants should be planted in relatively acidic soil. The specific site conditions are as follows:
1. Mostly planted on hills, with good drainage.
2. Prefers warmth and moisture.
3. Mostly planted in acidic soil climates such as spring, with abundant sunshine, sufficient rainfall, and relatively high soil and air humidity. Red soil, yellow soil, sandy soil, and brown forest soil are suitable, at an altitude of 1500m in places shrouded in mist and clouds.
Growth habits of tea plants:
[Soil]: Generally, a sandy loam with a soil layer more than 1 meter deep that contains no limestone, good drainage, organic matter content of 1%-2% or more, good aeration, water permeability, or water retention, and a pH value of 4.5~6.5 is suitable.
[Rainfall]: Average rainfall, with annual rainfall above 1500 millimeters. Both insufficient and excessive amounts have an impact.
[Sunlight]: Light is the primary condition for the survival of tea plants. It cannot be too strong or too weak. They have a special preference for ultraviolet light, hence good tea comes from high mountains.
[Temperature]: First, air temperature; second, soil temperature. The daily average air temperature needs to be 10 degrees; the lowest cannot be below -10 degrees. The annual average temperature is 18 to 25 degrees Celsius.
[Terrain]: Terrain conditions mainly include altitude, slope, and slope aspect. As altitude increases, both temperature and humidity change noticeably. In mountainous areas at a certain height, rainfall is abundant, mist and clouds are plentiful, air humidity is high, and diffused light is strong, which is beneficial to the growth of tea plants. However, it is not that the higher the better; above 1000 meters, there may be freeze damage. Generally, a south-facing slope is preferred. The slope should not be too steep, generally required to be below 30 degrees.
Tea plant, original name: tea, Latin name: Camellia sinensis (L.) O. Ktze., Theaceae, Camellia genus, shrub or small tree, young branches hairless. Leaves leathery, oblong or elliptical. The leaves of the tea plant can be used to make tea (different from the oil tea plant), the seeds can be pressed for oil, and the tea plant's wood is fine-grained and can be used for carving. Its distribution is mainly concentrated between 16 degrees south latitude and 30 degrees north latitude. Tea plants like a warm and humid climate. When the average temperature is above 10°C, the buds begin to sprout, and the optimum growth temperature is 20~25°C; annual precipitation must be above 1000 millimeters; it likes light and tolerates shade, and is suitable for growing under diffused light; its life is divided into the seedling stage, young stage, mature stage, and aging stage. The tree age can reach one to two hundred years, but the economic age is generally 40~50 years.
What are the environmental and soil requirements for planting tea plants?
1. Choose high-quality tea seedlings. It is best to use 1.5-2 year old cutting seedlings. For the diameter of the main stem at the base, large-leaf varieties require more than 0.5cm, and medium- and small-leaf varieties require more than 0.3cm.
2. Carry out hardening-off treatment before leaving the nursery.
(1) Water and fertilizer control. Because tea seedlings are managed under nursery conditions with sufficient water and fertilizer, the plants grow vigorously, the tissues are tender, and stress resistance is poor. Three months before leaving the nursery, fertilization should be stopped, and water supply should also be reduced as much as possible according to climatic conditions, with the aim of not damaging the tea plants through drought. Tea plants that have undergone hardening-off treatment may look somewhat poorer in appearance, but their survival rate is high. This can also serve as a reference when purchasing seedlings.
(2) Thinning the shade frame. Tea seedlings grow in the nursery for a long time, so their adaptability to light is poor, their shade tolerance is strong, and they are relatively sensitive to light. Because the light in the field is stronger, they are easily scorched. In addition, strong light can inhibit plant growth and has the effect of promoting dwarfing, strengthening the plant, and aging. Therefore, before leaving the nursery, thinning the shade frame can increase light transmittance, strengthen the light adaptation of the seedlings, and improve the quality of the seedlings.
Carry out timely pruning and timely topping. After tea seedlings have grown for 1 year, when the seedlings grow to 15-20cm, cut off the main axis at 10-20cm above the ground to promote branching and improve seedling quality. Half a month before leaving the nursery, first top them by removing the terminal buds of the main and lateral branches, to promote the tender tissues of the tea seedlings to age and mature, reduce the tender tissue and organs of the tea seedlings, and improve stress resistance. At the same time, it also promotes plump axillary buds.
When lifting seedlings, do not pull them out by hand; use a hoe to dig them out, injuring the roots as little as possible and keeping as much soil as possible. If tea seedlings are to be transported elsewhere, only lightly tap the root ball so that coarse soil falls away, while retaining as much of the fine soil adhering to the fine roots as possible. It is best to dip the roots in yellow mud slurry and wrap the base of the tea seedlings with straw or woven bags.
After the tea seedlings are transported back, they should be placed in a cool place and sprayed with water to maintain moisture. Prevent the seedlings from being exposed to wind and sun or being tightly pressed and piled up. At the same time, plant them promptly to ensure the seedlings remain fresh and alive; otherwise, the seedlings will lose water, their vitality will decline, and the survival rate will be affected. However, planting must ensure quality. Small trenches should be opened for planting according to specifications and requirements. If the tea seedlings cannot be planted within two days, they should be heeled in temporarily, that is, the tea seedlings should be temporarily concentrated on a small area of land without wind and without standing water, with the tea plant roots buried in the soil, and watered thoroughly. If the temporary heeling-in period is relatively long, then a sheltered, cool plot with good drainage must be chosen, trenches of suitable depth dug, and the seedlings arranged individually without overlapping, with the roots spread out and the soil firmed. Water them every day to keep the soil moist so that the tea plants survive, and then, according to the schedule, take out seedlings while planting.
How should tea plants be transplanted?
Use the trench planting method. On the basis of comprehensive reclamation, dig planting trenches 60×50ccm in width. Apply base fertilizer and mix it evenly with the soil, then cover with a thin layer of soil. The thickness of the surface soil should be based on the principle of avoiding direct contact between the root system and the fertilizer. Then open the planting trench, with a depth suitable for fully spreading the tea roots. The planting depth of tea seedlings should be appropriate, generally following the principle of maintaining the original position of the tea seedlings, and covering with soil slightly higher to prevent settling. Place the tea seedling into the trench, hold the seedling body with the left hand so that the tea seedling is vertical in the trench and the root system remains spread out, then with the right hand cover the soil to bury a small half of the roots, slightly lift the tea seedling upward with the left hand to spread the root system, and press the surrounding soil with the right hand so that the lower roots and soil are in close contact. Continue to level the soil from both sides of the trench into the trench, burying soil up to the original position of the root soil from the seedling stage, properly firm the soil around the tea plant, and then immediately water with root-setting water. The water should be applied until the root soil is completely moistened, watering while planting. Root-setting water must be applied regardless of whether it is sunny or rainy. This is one of the important measures for the survival of tea seedlings, because there is a lot of air between the new tea plant roots and the soil, and without complete contact, the roots cannot absorb water from the soil. After transplanting is completed, in order to reduce water transpiration and so on, some branches and leaves may be cut off as appropriate with pruning shears. Especially when transplanting tea seedlings with luxuriant branches and leaves or in dry conditions, pruning can play a role in increasing the survival rate. When pruning, there is no need to require uniformity; generally, leave 1-3 leaves above the branching position and cut. After pruning, small seedlings should still retain a certain amount of leaf area. The cut should be smooth, and the distance from the nearest leaf attachment point should be moderate, generally about 1 centimeter, not too long or too short.
Water management must be strengthened. Whether tea seedlings survive after planting depends most importantly on water management. Therefore, after planting, watering and irrigation must be carried out to keep the soil moist. According to climatic conditions, in dry seasons, one week after planting, watering once a day is required, and then gradually reduced; watering should be done in the afternoon or evening each day, not at noon under strong light and high temperature. The water must be applied thoroughly. Where there is dry wind from the north, more watering should be done. Where conditions permit, irrigation can be carried out during drought, but in appropriate amounts; in rainy weather, drainage work should be done well, especially in heavy rain or torrential rain, and water should not be allowed to accumulate for a long time.
In addition, tea seedlings have strong shade tolerance and are relatively sensitive to light. When transplanted from the nursery to the field, their adaptability to light is poor. Because small seedlings are tender, their leaf cuticle is thin, and transpiration is high, they are easily scorched. Therefore, after transplanting, if water loss is severe, shading methods can be used. Where conditions permit, shade sheds can be built, or branches and leaves can be used for shading. After young tea plants are planted, because new tea gardens often have few trees, soil temperature is high, water evaporation is high, and tea plants root shallowly, they are extremely susceptible to damage from high soil temperature and drought. Spreading grass (rice straw or dry grass) around the root zone of tea plants can lower the soil surface temperature, reduce water evaporation, and increase soil moisture, achieving the effect of being warm in winter and cool in summer. It is required to spread rice straw or dry grass over all the empty space on both sides of the tea seedling rows, with a thickness of about 2-3cm, so that bare topsoil is basically not visible in the tea garden.
Shallow tillage can loosen the surface soil layer, cut off soil capillaries, reduce water evaporation, and play a role in water conservation. Newly built tea gardens have large gaps between rows, and weeds are likely to grow in spring and summer, easily leading to pests and diseases, competing with tea seedlings for water and nutrients, and affecting tea plant growth. Interplanting green manure crops in young tea gardens can play a shading role while also reducing weeds and soil erosion in the tea garden, making it a measure that achieves multiple benefits at once.