How should stump bonsai be cared for in winter when temperatures are low?
1. Moderate watering, no fertilizing
In winter, watering should follow the principle of preferring dry over wet; do not water unless the soil turns pale. Water at noon, and water thoroughly in one go. Do not water in the evening, otherwise the plant is prone to frost damage. For coniferous, wax-leaf, and landscape trees with dense, thick, lush green foliage, spraying water to rinse the leaf surfaces is also very beneficial. In winter, bonsai trees should not be fertilized, but 15 days before the onset of winter, while weeding and loosening the soil and killing pests and diseases, apply one fertilizer mainly of phosphorus and potassium, so as to strive for robust plant growth before winter and improve cold resistance.
2. No pruning, eliminate pests and diseases
In winter, temperatures are low and growth vigor is low, so pruning is generally not advisable.
Pest control in winter can reduce pest and disease damage in the following year. Before the onset of winter, spray the entire tree once with an equal-strength Bordeaux mixture to prevent diseases. If holes are found in the trunk, they can be plugged with medicated cotton, or painted with mud mixed with lime powder and sulfur powder to kill overwintering insect eggs. For the underground part (including the potting soil), dilute a mixture of dimethoate emulsifiable concentrate and dichlorvos and pour it in to kill insects.
3. Ensure light, prevent cold and freezing
Different plants need different light durations. For example, conifers such as pines and cypresses, evergreen small-leaved banyan, Sageretia thea (Chinese sweet plum), and Chinese privet need longer light exposure, ideally 8 hours a day. For less cold-tolerant plants such as Aglaia odorata (mock lime), Lantana camara (shrub verbena), and Murraya paniculata (orange jasmine), when the temperature falls below 6 degrees Celsius, cover them with plastic film for protection or move them to a sunny spot.
How to care for stump bonsai well when the weather turns cold
Winter is the season when bonsai die most frequently. Whether watering or pruning, the slightest improper action can cause the potted plant to die, so we need to pay extra attention. Duorou Huapu will explain the precautions for everyone.
1. Moderate watering, no fertilizing
In winter, watering should follow the principle of preferring dry over wet; do not water unless the soil turns pale. Water at noon, and water thoroughly in one go. Do not water in the evening, otherwise the plant is prone to frost damage. For coniferous, wax-leaf, and landscape trees with dense, thick, lush green foliage, spraying water to rinse the leaf surfaces is also very beneficial. In winter, bonsai trees should not be fertilized, but 15 days before the onset of winter, while weeding and loosening the soil and killing pests and diseases, apply one fertilizer mainly of phosphorus and potassium, so as to strive for robust plant growth before winter and improve cold resistance.
2. No pruning, eliminate pests and diseases
In winter, temperatures are low and growth vigor is low, so pruning is generally not advisable.
Pest control in winter can reduce pest and disease damage in the following year. Before the onset of winter, spray the entire tree once with an equal-strength Bordeaux mixture to prevent diseases. If holes are found in the trunk, they can be plugged with medicated cotton, or painted with mud mixed with lime powder and sulfur powder to kill overwintering insect eggs. For the underground part (including the potting soil), dilute a mixture of dimethoate emulsifiable concentrate and dichlorvos and pour it in to kill insects.
3. Ensure light, prevent cold and freezing
Different plants need different light durations. For example, conifers such as pines and cypresses, evergreen small-leaved banyan, Sageretia thea (Chinese sweet plum), and Chinese privet need longer light exposure, ideally 8 hours a day. For less cold-tolerant plants such as Aglaia odorata (mock lime), Lantana camara (shrub verbena), and Murraya paniculata (orange jasmine), when the temperature falls below 6 degrees Celsius, cover them with plastic film for protection or move them to a sunny spot.
How to prevent freezing in stump bonsai in winter
Balcony stump bonsai need special care in winter, and freeze prevention is the key point. Today we will talk about how to prevent freezing in stump bonsai in winter. Let's take a look.
Balconies generally face south, but many also face north. If the balcony faces north, then when the temperature is below 0 degrees Celsius in winter, all kinds of stump bonsai should be moved indoors to prevent the roots from freezing and being damaged. For south-facing balconies, the temperature is generally 1-2 degrees higher than north-facing balconies, and the light is also better. Therefore, except for some cold-sensitive tree species, the others can be allowed to enter normal dormancy in a low-temperature environment. This can both enhance their cold resistance and kill pests and diseases.
What everyone needs to be reminded of is that in winter, attention should be paid to guarding against the invasion of strong cold air. Special attention should be paid to weather changes. All stump bonsai must be moved indoors before the arrival of a strong cold current (-5 degrees Celsius), and even the most cold-tolerant plants are no exception.
Some people may say whether cold-tolerant plants do not need freeze protection. The reason cold-tolerant plants can withstand cold is that the plant roots grow downward without limit in nature. As everyone knows, the underground temperature is relatively stable. No matter how frozen it is above ground, the underground remains unchanged, just as well water is warm in winter. Cold-tolerant plants benefit from the protection of ground temperature. Even if the above-ground branches and trunks are frostbitten or even frozen to death, as long as the root system is not frozen, it will still grow again when the weather warms in spring. But potted plants on balconies are different. Stump bonsai generally use shallower pots, with shallow pots and little soil, and the tree roots are exposed. In winter, cold wind blows under the pot, and snow and frost freeze above the pot. The entire stump bonsai is like being placed in a large freezer. If a strong cold current is encountered again, the stump roots will inevitably be thoroughly frozen and damaged. Once the stump roots are frozen and damaged, the plant becomes a tree without roots and will soon die.
There are many such cases. A few years ago, East China suffered an invasion of a strong cold current rarely seen in many years. The temperature suddenly dropped to -10 degrees Celsius. Many people neglected precautions, causing many stump bonsai that had been cared for for many years and had very high ornamental value to freeze to death because they could not withstand it. Especially for the stump bonsai kept on balconies, almost 60-70% froze to death. Even the relatively cold-tolerant elm could hardly escape disaster. This lesson is extremely painful.
On the ground, whether planted in the ground or in pots, the degree of loss is much lighter than on balconies in rough comparison. Because in winter the wind on high-rise balconies is particularly strong and especially dry, water should be sprayed on the branches and trunks more often at irregular intervals according to weather conditions, and special care should be given to some older stumps with more aged, withered surfaces. The branches and foliage must not be left too dry for a long time or even lose water. Otherwise, the branches may not withstand the invasion of severe cold dry wind and lose branches and foliage, and in serious cases the trunk will also partially die. In particular, Sageretia thea (Chinese sweet plum) is more likely in this season to lose branches and foliage due to drying and dehydration. Special attention should be paid, and it must not be neglected.
Growing stumps on balconies is more difficult than caring for them on the ground, and they often fail to thrive after repeated attempts. The key is that balconies lack the climatic conditions for normal stump growth. Therefore, improving the balcony microclimate and cultivating an environment suitable for the growth habits of stumps is the only way to grow stump bonsai well on balconies.
I. Analysis and improvement of balcony climate.
1. Analysis of balcony climate characteristics: Balconies have air circulation, good light, and rarely waterlogging, which are advantages; wind from all directions, large water consumption, dry air, side lighting, high temperatures in midsummer, and severe cold in deep winter are disadvantages. Moreover, these unfavorable climate conditions become more serious as the balcony floor increases. Balcony climate also differs depending on orientation: south-facing balconies have long sunshine duration and high temperatures; north-facing balconies have short sunshine duration and lower temperatures; east-facing balconies receive morning sunlight and have relatively large temperature changes; west-facing balconies receive afternoon sunlight and temperatures rise sharply; the climate changes of other offset balconies are each close to those of the directly facing balcony on the same floor.
The above analysis points out that the focus of improving balconies should be placed on regulating temperature, increasing humidity, and managing wind damage. Among these, increasing humidity is the key point among key points.
2. Specific methods for improving the balcony microclimate:
(1) Shading: A climbing flowering plant (such as grape or honeysuckle) can be planted in one corner of the balcony, with a trellis set up for it to climb and provide shade, or bamboo blinds, reed stem blinds, or woven wire mesh curtains can be hung for shading, turning harsh sun exposure into dappled shade. Also, at noon when the sun is strong, a white cloth curtain (about 1 m wide) can be propped up and hung on the balcony eave for shading. If no shading equipment is available, the stump bonsai should be moved to a shady place when the sunlight is strong.
(2) Wind blocking: For a balcony open on three sides, large glass windows should be installed at both ends to block wind. Or wooden boards, hard cardboard, etc. can be used to close off the west and north ends of the balcony, while the east and south ends can be combined with hanging shading curtains to weaken the wind force. Because wooden boards and hard cardboard are not light-transmitting, they can only be used to close off the north end of east- and west-facing balconies, and the west end of south- and north-facing balconies. In this way, first, light is not affected, and second, the west and north winds can be blocked and air convection weakened. The front side of the balcony should not be closed, so as to facilitate the stump bonsai receiving sunlight and rain. Second, attention should be paid to closing the doors and windows on the inner wall of the balcony, cutting off air channels, reducing flow speed, and preventing wind damage.
(3) Sprinkling water on the ground to retain moisture: (1) On the upper part of the inner wall of the stump-growing balcony or above the railing, install a thin water pipe as long as the balcony, with several thin nozzles installed on the thin water pipe (if the water pipe is installed on the inner wall, the nozzle openings face outward and downward; if the water pipe is installed above the railing, the nozzle openings face outward and downward), connect it to the tap water pipe, and except in winter and early spring, open the valve several times a day to spray water, keeping the balcony often in a moist state; (2) About 5 cm thick coal cinder ash or fine sand can be spread on the balcony, covered with bamboo or wooden stepping boards or with a walkway left out for convenient walking, and watering to soak the coal ash (river sand) thoroughly. The moisture in the wet coal ash gradually evaporates, increasing balcony humidity; (3) Spread burlap pieces, thick cloth pieces, or straw-woven mats on the balcony floor, water them thoroughly, and let evaporation retain moisture; (4) Directly sprinkle water on the balcony to retain moisture; (5) In spring and autumn, when water consumption is high, some thick wet cloth pieces can be hung to dry on the balcony, and the evaporating water increases air humidity; (6) Appropriately place the stump bonsai pots closer together, so that the moisture released by the potting soil and branches and leaves mutually moistens them.
(4) Spraying water on branches and leaves: In seasons when branches and leaves evaporate a large amount of water, a sprayer should often be used to spray water on the stump bonsai to keep the branches, trunks, and leaves moist. Second, the stump bonsai pots should be placed within the balcony railing, so that the created balcony microclimate can take effect.
The above methods should be selected flexibly according to each person's specific conditions, balcony situation, and different seasons.