Yellow leaves, root rot and few flowers: key points for root care explained
Many gardeners say that growing flowers means growing roots: only when the roots are well cared for can the branches and leaves be lush and green, and only then will the flowers bloom abundantly and vividly. The most common problems in everyday flower growing are yellow leaves, root rot and few flowers, and most of these are closely tied to the plant's roots. Plants are meant to grow in the natural earth, yet we plant them artificially in a small flower pot, sometimes even keeping them indoors, so whether in terms of soil, temperature or sunlight, the environment more or less goes against the plant's nature.
Under such conditions, how can you grow the roots well and make the plant stronger? Only by absorbing enough water and breathing in enough oxygen can a plant better deliver nutrients to its branches and leaves, growing more and more vigorous.
Plants absorb water in two ways: active and passive.
When growing flowers, many gardeners notice that Alocasia amazonica (elephant ear), pothos and areca palm all show water dripping and guttation from their leaves. When we break or cut the stems of flowers and plants, water or liquid flows from the wound; this is called "bleeding". This is a sign of active water absorption by the plant. The more active the root system, the stronger its water-absorbing capacity, so both guttation and bleeding can serve as signs that a plant is growing well.
Active water absorption happens because the plant is internally transporting mineral nutrients, which creates the water-absorbing effect; the healthier the plant, the stronger its active water absorption, while passive water absorption is caused by transpiration from the leaves, which lowers the water pressure on the leaf surface and draws soil moisture upward. In a high-temperature environment, leaf transpiration is strong; if there is not enough water in the soil, the water lost from the leaves cannot be replenished in time, and the leaves will wilt, scorch, or even the stems and leaves will dry up and die. This is why people always say you need to water more in summer.
The basic condition for healthy roots is aerobic respiration. Only by absorbing water and the oxygen in the soil can effective oxidation reactions be triggered, setting the plant's internal systems in motion.
Why do people always say the soil should be loose? Why ventilate frequently? Why do plants become unhealthy when the soil is compacted? Insufficient fertility is one aspect, but insufficient oxygen is an even bigger problem.
During plant growth, temperatures that are too high or too low will both affect root respiration and weaken the roots' ability to actively absorb water. If you water heavily at such times, black rot and root rot are very likely to occur, which is what we commonly call plant dormancy or slow growth. The importance of temperature and oxygen to roots also explains why compost must be thoroughly decomposed. The fermentation process of fertilizer not only generates heat but also produces carbon dioxide. If it is not fully decomposed and comes into contact with the roots, the result is that the temperature is too high, root vigor drops or the roots are directly burned, and the proportion of carbon dioxide in the soil rises, which also affects respiration.
Therefore, undecomposed fertilizer must never come into contact with the roots of flowers and plants. By now, dear gardeners, I believe you can understand how important water, temperature and oxygen are to plant health.
What to do when flowers and plants develop root rot? Adding these things works wonders
When you grow all kinds of flowers and plants at home, the most feared and most common problem is root rot. Once root rot occurs, not only does the plant look bad with yellow, wilted leaves and fail to set buds and bloom, but even if it does bloom, the flowers soon drop.
The causes of root rot include excessive fertilization or undecomposed soil, but the most common is too much water in the potting soil, which affects root respiration and causes root rot.
Improving the potting soil is the best way to correct the root rot problem. Add the following materials to the potting soil and the soil drainage problem will be solved in no time, so your flowers and plants at home will never again suffer from yellow leaves, root rot or death, and will grow lush and ever more beautiful.
Pine needle soil
Pine needle soil has good air permeability. Used for growing flowers, added to the soil it greatly improves soil drainage. At the same time it is slightly acidic with long-lasting fertility, so it works very well for acid-loving plants.
The most common flowers that use pine needle soil include clivia, camellia, azalea, clematis and crabapple. It is not suitable for alkaline-loving plants.
In addition, pine needle soil is light in weight, and used alone it leaches water and fertilizer, which is bad for root anchoring and growth, so it needs to be combined with other soils.
Clay pebbles
Clay pebbles are large-grained, drain well and allow air through, and carry no bacteria. Gardeners often use them as a layer at the bottom of pots to increase soil drainage and aeration. Gardeners who grow orchids also add clay pebbles to the potting soil to avoid root rot.
Besides drainage and aeration, clay pebbles can also be spread on the surface of the pot; in summer they help maintain soil temperature and humidity.
Clay pebbles used for growing flowers likewise lack nutrients and need other soil media added; generally a clay pebble proportion of one-fifth or less is enough.
Perlite
Perlite is the common white granular material inside the nutrient soil we buy, a bit like plastic foam. Perlite hardly absorbs water, can increase soil drainage and at the same time improve the soil texture, preventing soil compaction.
Perlite itself has little nutrient value. If used to increase drainage, adding about one-fifth to the potting soil achieves a fairly good effect.
Coarse sand
Sand itself has no nutrients or fertility, but sand does not absorb water and is an excellent drainage material; mix an appropriate amount of river sand into flower soil and you never need to worry about waterlogging again.
When using it, add leaf mold and a small amount of base fertilizer, and it can basically meet the soil needs of most flowers at home, from pothos, spider plant and aloe to gardenia, jasmine and money tree. Generally the sand proportion is one-third or one-quarter.
River sand you collect yourself should be washed clean before use, then soaked in cooled boiled water for two days; this removes the sand's salinity and alkalinity and reduces the occurrence of plant diseases.
Coal cinders
Coal cinders, as household waste, are very effective for growing flowers. Their internal structure is porous, and they are granular themselves, so drainage and aeration are very good. They were previously mostly used in succulent growing, and now gardeners have discovered many other clever uses for them in growing and caring for other flowers and plants.
When blending coal cinders with other soils, the proportion can range from one-fifth to one-half depending on the situation. Compared with the three media above, coal cinders themselves contain more trace elements that plants need, such as calcium, magnesium and iron; add humus soil and they can basically meet the growing needs of ordinary flowers and plants.
Opposite to pine needle soil, coal cinders are slightly alkaline. When using them, be sure to choose thoroughly burned coal, crush it into small granules, wash and soak it in water to remove dust and the alkaline substances in the cinders, then sift out the larger granules for mixing flower soil; the aeration and drainage effect is very good. Do not throw away the small granules either; they are perfect for raising seedlings.
When flowers and plants develop root rot, next time you change the soil, remember to add these materials; with good drainage, you will never fear root rot again!
Overwintering care and management of flowering potted plants and bonsai
The low temperatures and frosty weather of winter can pose a serious threat to flowers and trees. To get flowers and trees safely through winter, the first thing is to follow the principle of "do not bring in during winter, do not take out during spring". "Do not bring in during winter" means that when the weather first turns cold and there is no frost, for most flowers you should not rush to move them indoors. "Do not take out during spring" means that when the weather turns warm, do not rush to move them outdoors; wait until the last late frost of spring has passed and the weather has fully improved before starting to move them outside.
Five key elements and precautions for overwintering care and management of flowering potted plants and bonsai
1. Understand the cold tolerance temperature of the flowers:
Depending on the different low-temperature tolerance of different flowers and trees, take different cold-proof and warmth-keeping measures, either moving the flowers and trees directly indoors, covering the pot with plastic film, slipping a plastic bag directly over the plant, or setting up a temporary simple mini-greenhouse for warmth. For flowers and trees with strict light requirements, place them on an indoor windowsill or near a windowsill where sunlight is plentiful; for those with less strict light requirements or that tolerate shade, place them in a shaded spot without light, but in all cases pay attention to ventilation and air flow. It is best to open the windows for ventilation at noon on a sunny day, but do not let cold wind blow directly on the flowers and trees.
1. For cold-tolerant flowers that can handle low and cool temperatures (5-12°C, below 5°C), such as pomegranate, Chinese rose, wintersweet, osmanthus, palm, Chaenomeles speciosa (flowering quince) and crape myrtle, they can be placed in an outdoor courtyard or on a sunny balcony.
2. For flowers that need to be kept at medium temperature (12-20°C), such as white orchid, camellia, azalea, banana shrub, clivia, fuchsia and begonia, they must be moved indoors before the temperature drops to 10°C.
3. For flowers that can grow normally only at high temperature (18-30°C), such as Aglaia odorata, Chinese hibiscus, jasmine, croton, narcissus, epiphyllum, orchid cactus, cactus, fortune tree, spider plant, pothos, Chinese hibiscus, poinsettia, begonia, jasmine, Monstera deliciosa, ball cacti and aloe, they must be moved indoors before the temperature drops to 12°C.
After plants are moved indoors, their placement also matters. They should be placed in a sunny, warm spot. Put sun-loving plants in front, and semi-shade-tolerant or shade-tolerant potted flowers behind, and also rotate their orientation from time to time. In the first week, open the windows for ventilation so the plants gradually adapt to the temperature change. Potted flowers moved indoors, both for appearance and to ensure effective nutrient absorption.
For plants placed outdoors, a windbreak can be set up for cold protection. Common cold-proof measures include mounding soil around the roots and stems and covering with soil. Mounding soil around the roots and stems means building a small mound of soil at the root collar of the tree to prevent low temperatures from freezing and damaging the root collar and tree roots, while also reducing soil moisture evaporation. For flowers like peonies that are planted in the ground and cannot be moved indoors, you can turn a large basket over the whole plant, coat the basket with a layer of mud, making it like a warm, humid mini-greenhouse.
2. Pruning before overwintering:
Before potted flowers overwinter, they should be pruned and shaped in good time to reduce nutrient consumption and reduce the indoor space they take up during winter. Potted flowers moved indoors, both for appearance and to ensure effective nutrient absorption, must be pruned; cutting away withered leaves, overly dense branches, diseased and pest-infested branches, and weak branches fully supplies nutrients to the effective branches so the potted flowers grow strong and pass the winter safely. For leggy branches, pruning can be done more heavily. Binding materials on bonsai that have been shaped for 1-2 years can be removed, or removed and then re-bound, to prevent long-term binding at fixed positions from injuring the cambium of the branches and causing the branches and leaves to die. For tree-stump bonsai placed on balconies, such as Chinese elm, plum, trident maple, banyan, Podocarpus macrophyllus (buddhist pine), Chinese juniper and dragon juniper, necessary pruning must be carried out. For jasmine, crape myrtle, pomegranate and the like, pruning can be done in late autumn to reduce the plant's nutrient consumption in winter, help the potted flowers store more nutrients and make them bloom more the following year. Dead branches, densely growing branches, diseased and pest-infested branches, overly old branches and damaged branches can all be removed with a sharp knife or sharp scissors; for those that bloom in spring, only appropriately thin out the autumn shoots without flower buds; for those that bloom on the current year's branches, pruning should be strengthened to promote new shoots and prepare for flowering the next year; for those already frost-damaged but still partly alive, heavy pruning can be carried out, while strengthening fertilizer and water management, so the flowers and trees quickly recover their growth.
3. Fertilization precautions for overwintering:
Apply fertilizer once before overwintering and water thoroughly. During overwintering, flowers generally should stop being fertilized. For flowers and trees in dormancy or semi-dormancy, fertilization should stop to avoid root rot, and fertilizing should wait until repotting in spring; for flowers and trees that bloom in autumn, winter or early spring, and for autumn-sown flowers and trees, a light fertilizer is suitable. To improve the cold resistance of flowers and trees, fertilization should be reduced in late autumn so the stems and leaves do not grow tender and lower their cold resistance.
4. Watering precautions for overwintering:
In winter, flowers and trees grow slowly, their metabolism slows, and most enter dormancy, so their water requirement and evaporation decrease relatively. The principle for watering is "better dry than wet"; never water before the potting soil is dry, especially for shade-tolerant flowers, and do not water too much, to avoid leaf drop, root rot or death. Generally it is best to water thoroughly only after the potting soil has dried out. The water temperature is best close to room temperature; you can also water flowers with warm water at 20-25°C. Watering flowers with warm water accelerates the decomposition of organic matter in the potting soil and promotes the absorption of nutrients by root cells, thereby promoting flower growth. The best time to water is at noon when there is good light. If using tap water to water flowers, it is best to let it stand for 1-2 days first, and use it after the chlorine in the water has evaporated. At the same time, avoid watering flowers with water containing soap or laundry detergent. While watering, you can carefully wipe the dust off the leaf surfaces with a damp cloth.
5. Ventilation precautions for flowers brought indoors:
Remember to ventilate regularly, preferably on a sunny day when the sun is out, or at noon when the temperature is higher. When ventilating and changing the air, you must also be careful not to let cold wind blow directly on the plants, to avoid adverse reactions.
6. Pest and disease control during overwintering:
For flowers and trees whose leaves are prone to pests and diseases, such as crabapple, rose and camellia, collect the dead branches and fallen leaves under the plants and burn them, which can reduce disease occurrence the following year. At the same time, spray carbendazim for sterilization and disinfection. For powdery mildew, rust and primula gray mold, promptly use triadimefon or thiophanate-methyl respectively for control. For flower and tree species on which aphids often appear on potted plants when ventilation is poor, such as white orchid and Aglaia odorata, imidacloprid can be used for control. For scale insects, of course, the highly targeted Jiebijiezhi must be used for control. Common diseases of flowers and trees in winter include powdery mildew and sooty mold, and common pests include aphids, whiteflies and scale insects; effective measures should be taken to control them during the dormant period, to reduce the occurrence of pests and diseases in the following spring.
Next year when spring begins, generally during the period from the Spring Equinox to Qingming, overwintered flowers can successively be moved outdoors and given fertilizer and water, such as bio-organic fertilizer, yellow-leaf remedy and trace-element water-soluble fertilizer, so the flowers grow normally in spring.