How to prevent and treat yellowing and dropping leaves on chrysanthemums?
During the growing process, chrysanthemums often show yellowing and dropping leaves, mainly caused by insufficient fertilizer and water, slowed plant growth; overly wet potting soil, excessive fertilizing; fertilizer solution splashing onto the leaves during fertilizing and soiling them; and pest and disease attacks. To prevent yellowing and dropping leaves on chrysanthemums, the main points to pay attention to are the following:
First, fertilizing. When fertilizing chrysanthemums, master the principle of light fertilizer applied frequently, and slightly stronger after flower buds appear. For topdressing, use 2 parts decomposed soybean cake or sesame oil residue plus 8 parts clear water, applying once every 7 to 10 days. After buds appear, use 1 part fertilizer plus 3 parts water, mixed with a small amount of potassium dihydrogen phosphate for topdressing. After applying, promptly rinse the fertilizer solution off the leaves with clear water.
Second, watering. Water the flowers according to the principle of "water when the potting soil is dry, do not water when it is not dry, and water thoroughly when you do". In summer the weather is hot and the potting soil dries easily, so water adequately, but do not water at noon; water sufficiently in the morning, and if the potting soil is dry in the evening, water once more. After rain, tip the pot to drain off the water. When watering, avoid splashing soil onto the leaves.
Third, prevent and control pests and diseases. The disease that mainly harms chrysanthemum leaves is leaf blight.
The control method is: starting in spring, spray once every 15 days with 500 times diluted wettable amobam or zineb. For chrysanthemum aphids, spray with 40% omethoate; for red spider mites, spray with 1000 times diluted propargite solution.
Causes and prevention of yellowing and dropping leaves on chrysanthemums
According to the editor's own experience of growing chrysanthemums, generally when fertilizing, the fertilizer water must not touch the branches and leaves of the chrysanthemum, otherwise it will cause the leaves to wither and yellow. After fertilizing, promptly use a spray bottle to spray clear water on the chrysanthemum plant to wash off the fertilizer solution clinging to the leaves, so as to prevent the chrysanthemum leaves from yellowing and dropping.When yellowing, withering and dropping of the lower leaves occurs during chrysanthemum cultivation, this is called foot leaf drop, commonly known as "bare feet". Foot leaf drop is a common problem that also gives chrysanthemum growers a headache, hence the saying in flower lore that "growing chrysanthemum flowers is easy, growing their leaves is hard". The bare, shed lower stem of the chrysanthemum not only affects the quality of blooming, making the plant top-heavy and unstable in its center of gravity, but also affects the overall ornamental effect. Therefore, to bring chrysanthemums up to a relatively high aesthetic standard, the lower foot leaves must be preserved and grown well. To prevent chrysanthemum foot leaves from dropping, first find out the causes of foot leaf drop, then achieve the goal of preserving the foot leaves through appropriate cultivation management.
The causes of foot leaf drop involve both internal and external factors. Because cuttings are taken too early, with about one year from cutting to blooming, by the time of blooming the lower part of the stem has mostly become woody; at this time the growth-regulating substances in the old leaves have changed, and this is the internal cause of chrysanthemum "bare feet". An unsuitable cultivation environment, such as improper watering, too much or too little, improper fertilizing, excessive or too concentrated fertilizing in summer, fertilizer solution or muddy water splashing and soiling the leaves, and damage from pests and diseases, are the external causes leading to chrysanthemum "bare feet".
In view of the above causes, to prevent chrysanthemum leaves from yellowing and dropping, the following methods can be adopted for treatment:
(1) Appropriately postpone the cutting period. Chrysanthemum leaves have a certain lifespan and also undergo metabolism. Only by keeping the foot leaves within the lifespan range of normal growth can the foot leaves be guaranteed not to drop. On the premise of ensuring the blooming period and shaping requirements, the time for cutting propagation can be postponed, for example to May to July, which can greatly reduce the occurrence of the "bare feet" phenomenon.
(2) Water and fertilize reasonably. Prevent the potting soil from becoming too dry or too wet. There is a saying in flower lore that "dry for pines, wet for chrysanthemums", indicating that chrysanthemums like moist soil conditions. Soil that is too dry will cause the leaves to wilt; although they can recover after watering, it easily leads to the foot leaves yellowing and dropping. At the same time, chrysanthemums also fear waterlogging; when the potting soil is too wet or water accumulates, it inhibits the respiration and absorption of the root system, thereby causing severe dropping of the foot leaves. Therefore, when cultivating chrysanthemums, note first that a good growing medium should be prepared and the drainage hole of the pot properly covered; second, do not let water accumulate in the pot, guard against rain in the rainy season, and raise the flowerpot up.
(3) Adopt the shallow planting method. That is, when potting chrysanthemum seedlings, put in only 1/3 of the pot's height of potting soil, and gradually add potting soil later as the plant grows taller, so that the leaves on the pot surface remain in a relatively robust state. Alternatively, at the time of final planting, press and bury the leafless basal branches into the potting soil.
(4) Keep the foot leaves clean. When watering or fertilizing, avoid fertilizer solution or muddy water splashing and soiling the leaves, because the surface of chrysanthemum leaves has fine hairs, and once contaminated by fertilizer solution or muddy water it will cause the foot leaves to wither, yellow and drop. When watering, fertilizing or raining causes potting soil to splash and soil the leaves, promptly spray water to wash the leaves clean, which can prevent the foot leaves from yellowing and dropping.
(5) Prevent and control pests and diseases in time. When chrysanthemums are attacked by pests and diseases, the leaves easily turn yellow and drop, so spray pesticides promptly for control.
What to do when chrysanthemum leaves turn yellow: solutions for yellowing chrysanthemum leaves
Chrysanthemums are fairly widely used flowers. Whether at home, in courtyards or other places, displaying chrysanthemums for ornament is still quite common. What should be done when chrysanthemum leaves turn yellow? Below, let us take a look at the solutions for yellowing chrysanthemum leaves.
1. Soil on the alkaline side
Chrysanthemums like fertile, highly permeable, slightly acidic soil. Soil with a pH above 7.5 very easily causes the lower leaves of chrysanthemums to drop or the leaves of the whole plant to turn yellow. Solution: regularly water with fermented rice-washing water or rainwater.
2. Watering too much
Watering too much causes the soil to stay waterlogged and wet for a long time, with poor aeration and even partial rotting of the fibrous roots, showing as the young leaves of the chrysanthemum being dull yellow and lusterless and the new shoots shrinking. Solution: water chrysanthemums according to the principle of watering when the potting soil is dry, not watering when it is not dry, and watering thoroughly when you do. In summer the weather is hot and the potting soil dries easily, so water adequately, but do not water at noon; water sufficiently in the morning, and if the potting soil is dry at dusk, water once more. After rain, tip the pot to drain off the water. When watering, prevent soil from splashing onto the leaves.
3. Watering too little
Because chrysanthemums have long gone without thorough watering or have become dehydrated, although the new leaves are normal in color, the lower leaves gradually dry, yellow, drop and age from the bottom upward. Solution: during the growing period chrysanthemums need adequate watering; after the potting soil dries, water once more, but note that you must not water when the sun is fairly strong at noon.
4. Too much fertilizer
Applying too much fertilizer to chrysanthemums can also cause the leaves to turn yellow. Solution: when fertilizing chrysanthemums, master the principle of light fertilizer applied frequently, and it can be slightly stronger after flower buds appear. For topdressing, use 2 parts decomposed soybean cake or sesame oil residue plus 8 parts clear water, applying once every 7 to 10 days. After buds appear, use 1 part fertilizer plus 3 parts water, mixed with a small amount of potassium dihydrogen phosphate for topdressing. After applying, promptly rinse the fertilizer solution off the leaves with clear water.
5. Damage from leaf blight
Infection by leaf blight is one cause of chrysanthemum leaves turning yellow and withering, mainly harming the flowers and leaves of chrysanthemums. Solution: spray once every 15 days with 500 times diluted wettable amobam or zineb.