Frost damage, waterlogging, and high temperatures with drought can cause significant physiological harm to white Tea plants, affecting their growth and even their survival.

I. Frost Damage

Frost damage can be divided into winter frost that causes physiological damage to the tea plant and spring frost that damages new shoots.

1. Winter Frost Damage

There are three situations: ice frost, snow frost, and dry frost. Ice and snow frost refer to continuous overcast rain and snow leading to ice and snow accumulation on the above-ground parts of the tea plant. Generally, snow cover does not affect the tea plant, but prolonged ice accumulation can lead to the rotting and death of leaves and small branches. In three-dimensional tea gardens, branches exposed to ice and snow may suffer more severe frost damage.

Tea garden ice and snow frost damage

Dry frost is mainly caused by low temperatures that freeze the soil, while the above-ground parts endure severe cold, exacerbated by dryness and strong winds. Mature branches and leaves in an adult tea garden will show varying degrees of frost damage at temperatures below -5°C. In severe cases, the damage can reach level 5, causing the death of crown branches, severely harming the next year's yield and the health of the tree. Under the same temperature, three-dimensional tea gardens often suffer more severe frost than flat tea gardens, and young tea gardens can be completely frozen to death.

Tea garden dry frost damage

Winter frost prevention measures include: applying organic fertilizer early and frequently, reducing inorganic fertilizer application, improving the plant's constitution and nutrient composition to enhance its cold resistance; using straw mulch to retain moisture and increase soil temperature; pruning tea plants after the end of winter, and avoiding mother gardens in areas prone to freezing.

2. Spring Frost Damage

Spring cold, primarily in the form of frost, can invade new shoots and buds, threatening Spring Tea production. Frost damage to new shoots occurs after the scales have unfolded (known as showing white), causing fish leaves and true leaves to freeze and die. With mild frost damage, the buds and leaves will still sprout, but the back of the leaves will exhibit a dark red color, affecting tea quality. Moderate frost damage results in necrosis of some or outer leaves, which can still maintain growth until the appearance of a bud with two or three leaves. Severe frost damage can result in a complete loss of spring tea harvest.

Moderate spring bud frost damage

Severe spring bud frost damage

Spring frost protection is even more critical than winter frost prevention. Key measures include: selecting suitable locations, varieties, and establishing windbreaks for basic protection; using facilities to prevent frost; closely monitoring weather forecasts after the emergence of tea buds and picking harvestable buds before a cold snap to minimize losses; and spraying water on the crown to remove frost.

Ice formation on tea leaves after spraying water to remove frost, exacerbating freeze damage

II. Waterlogging

The main forms of waterlogging that affect tea plants include standing water waterlogging, soaking from persistent rain, and wet heat soaking.

1. Standing Water Waterlogging

Long-term standing water often causes fatal damage to tea plants. In some low-lying slopes and areas near springs where tea gardens are planted, tea seedlings often develop poorly and gradually die. Similarly, in rice paddies and terraces with high groundwater levels and undisturbed plow layers, tea plants often die in batches over time. When winter arrives, accompanied by sudden low temperatures and ice, the branches and leaves of tea plants turn red and wither, and the roots rot, leading to the death of the entire plant.

Standing water waterlogging causing root rot and death

Standing water waterlogging causing red discoloration and shedding of leaves

2. Soaking from Persistent Rain

In sandy soil tea gardens on sloping land with good drainage, prolonged rainy weather during the winter and spring dormancy period, even without ice, can cause physiological disorders in the tea plant. Leaves may partially turn a reddish-brown color in milder cases and completely red in severe cases, leading to shedding.

Persistent rain soaking causing varying degrees of red discoloration in leaves

3. Wet Heat Soaking

In the spring, young White Tea plants growing well in saturated soil conditions and under high temperatures and humidity may experience leaf fall and death. To prevent waterlogging damage, it is essential to plan and prepare the tea garden properly during establishment, including constructing drainage channels, breaking up compacted soil layers, and improving the condition of the garden site. Drainage work should be carried out when the rainy season approaches, and tea gardens damaged by waterlogging can be improved through pruning, cleaning the soil, and enhancing the ecological environment of the garden.

Wet heat soaking causing leaf fall and branch withering in young white tea plants

III. High Temperatures and Drought

Protection against high temperatures and drought in white tea gardens is crucial but can be challenging in practice. Apart from choosing suitable garden conditions and the aforementioned soil cultivation, key measures include irrigation and shading.

During periods of continuous sunny days exceeding 15 days with high temperatures, attention should be paid to the water supply status of the tea garden soil and tea plants. In areas where conditions permit, watering should be carried out promptly if there is obvious stagnation in new shoot growth, abnormal leaf extension, or soil dryness, indicating a lack of water. For young tea gardens, liquid fertilizer applied once a month can effectively combat drought.

Shading in tea gardens can involve planting shade-providing trees at the time of planting, as well as intercropping young tea gardens with crops like long beans that have a small root system, short growth seasons, tall stems, or vines. Shade branches can also be used to provide shade during summer droughts. For young, easily drought-prone areas, and white tea gardens that whiten in summer and autumn, using a 50% shading rate shade net provides good control and significant effects.