What causes yellowing leaves in potted flowers?

Overwatering, over-fertilizing, dry air...

Do you know these 13 causes of yellowing leaves in potted flowers?

Because potted flowers are limited by the volume of the pot, their roots cannot spread freely downward and outward, so root development is hindered. If they are poorly managed, with improper watering and fertilizing, they are more prone to yellow leaves than flowers grown in the open ground.

The 13 causes of yellow leaves in potted flowers and the remedies are as follows:

(1) Overwatering

When the potting soil stays too wet for a long time, it causes a lack of oxygen in the soil, makes some fibrous roots rot, and hinders normal respiration and the absorption of water and nutrients, causing leaves to turn yellow and drop. After damage occurs, the young leaves first turn pale yellow, and then the old leaves gradually turn yellow as well. Watering should be controlled immediately, fertilizing suspended, and the soil often loosened so that it is well aerated.

(2) Drought and dehydration

Missing watering or long-term half-watering (that is, wet on top and dry below) affects nutrient absorption and also easily causes the leaf color to become dull and lusterless, with leaves wilting and drooping. First the lower old leaves age, and gradually dry up, turn yellow and drop from the bottom upward. At this point, water lightly and mist the plant, let it gradually recover, and then return to normal watering.

(3) Long-term lack of fertilizer.

If no nitrogen fertilizer has been applied for a long time or the pot and soil have not been changed, the soil lacks nitrogen and other nutrient elements, causing the branches and leaves to become thin and weak, with leaves thin and yellow. The plant should be repotted in time, changed into fresh loose, fertile potting soil, and gradually given more dilute, well-rotted liquid fertilizer or compound flower fertilizer.

(4) Over-fertilizing

If too much fertilizer is applied, new leaves will be thick and fleshy, and often uneven and bumpy, while old leaves will dry at the tips, scorch yellow and drop. Fertilizing should be stopped immediately, watering increased so that the fertilizer flows out through the drainage holes at the bottom of the pot, or the plant should be repotted at once, the root ball rinsed with water and then replanted in the pot.

(5) Hot, high temperatures

In summer, if flowers that prefer cool conditions (such as cyclamen, fuchsia, and wax begonia) are placed in a hot spot and exposed to direct strong sunlight, the tips and edges of young leaves are very likely to scorch, or the leaves turn yellow and drop. They should be moved promptly to a well-ventilated, shady place.

(6) Too much shade

If sun-loving flowers are kept for a long time in a shaded spot or a place with insufficient light, the branches and leaves will grow spindly, the leaves will be thin and yellow, and the plant will not bloom or will bloom very little. Take care to move the pot to a sunny spot.

(7) Soil and water too alkaline

In most areas of the north, the soil and water contain relatively more salt and alkali. When growing flowers that prefer acidic soil, such as rhododendron, camellia, banana shrub, gardenia, orchid, Michelia alba, and osmanthus, the leaves gradually turn yellow because the soil lacks soluble iron and other elements that the plants can absorb. When planting, choose acidic soil, and during the growing period often water with alum fertilizer water.

(8) Too dense and poorly ventilated

If too much nitrogen fertilizer is applied, the branches and leaves grow too luxuriantly, and if the plant is not pruned for a long time, the inner branches and leaves do not get enough light, which easily causes leaves to turn yellow and drop. Fertilize reasonably and prune more to give the plant good ventilation and light.

(9) Dry air

When the indoor air is too dry, some flowers that like a humid environment, such as spider plant and orchid, often show dried leaf tips or scorched leaf edges. Take measures such as misting and covering with plastic film to increase air humidity.

(10) Improper temperature

In winter, if the room temperature is too low, flowers that like high temperatures are often damaged by cold, which causes the leaves to turn yellow and, in severe cases, to wither, turn yellow and die. If the room temperature is too high, the plant transpires excessively, and the roots cannot supply enough water and nutrients, which also turns the leaves yellow. Take care to adjust the room temperature in time.

(11) Soil too acidic

In the south, red soil is acidic, and magnesium and other elements are easily lost. When growing trees and flowers that tolerate alkali or prefer slightly alkaline soil, such as oleander, boxwood, and winter jasmine, the old leaves often show yellowing between the veins. Calcium magnesium phosphate fertilizer can be applied or a magnesium sulfate solution sprayed.

(12) Damage from pests and diseases

Leaf spot disease caused by infection with fungi and other pathogens easily causes local necrosis of the leaves, with yellow spots or patches appearing, and in severe cases the whole leaf withers, turns yellow and drops. After infection by mosaic virus, yellow-green mottling appears on the leaves. When damaged by scale insects, red spider mites and the like, the leaves also become locally yellow and withered, or even the whole leaf wilts, turns yellow and drops. In all cases, spray promptly to control the problem.

(13) Strong irritation

When preventing and controlling pests and diseases, using pesticide at too high a concentration, or contamination by toxic gases in the air, or suddenly watering with cold water when the temperature is high, can all easily cause the leaf tips or parts of the leaf surface to turn yellow and scorch, or even the whole plant to wither and die. Therefore, use pesticides reasonably and find ways to eliminate sources of air pollution. In midsummer, avoid watering flowers with cold water around midday. Finally, it should also be mentioned that yellow leaves on potted flowers are sometimes caused by one reason, but are often the result of multiple factors, so a correct diagnosis should be made before treating the root cause.