What if the geranium leaves turn yellow? Causes of yellowing of pelargonium leaves and its solution

A kind of flower can be seen on the windowsill of many families, that is, geranium, especially abroad, which can decorate the streets and decorate life. For example, today, geraniums are becoming more and more popular in families, but problems are frequent and yellow leaves always appear. What should we do?

Cause analysis and treatment of yellowing of pelargonium leaves:

The main results are as follows: 1. the abrupt change of environment leads to the yellowing of geranium leaves: the yellowing of old leaves caused by changing environment. Before the summer high temperature comes, many flower friends will move the small sky indoors from the outdoor flower rack, or from the Nanyang platform to the north balcony, or from the all-day outdoor to the corridor, or put up a sunshade net for the flowers, and so on, the growth environment will suddenly change greatly, which will cause the old leaves of the geranium to turn yellow and the bud to dry up.

Solution: we do not need to worry too much, Xiaotian has a process of adapting to the new environment, just pinch off the big yellowed leaves and dry buds, and other normal management.

2. Too much watering leads to yellowing of geranium leaves: due to overwatering, too much watering, long-term over-wet basin soil, and high temperature, part of the root system of geranium is rotten, which is shown in the leaves that the old leaves have no obvious change and the tender leaves turn pale yellow. Serious old leaves will also appear yellow leaf shedding phenomenon.

Solution: this requires immediate water control, loose basin soil in a ventilated and dry place to speed up evaporation. Or put the flowerpot on a stack of newspapers or dry peat and let the newspaper and peat suck out too much water from the pot as soon as possible. If the situation is particularly serious, the whole clod can be protruded from the basin and placed in dry peat or mound to make the water seep out quickly, and then replant it into the basin after the drooping branches and leaves are restored.

3. Long-term lack of water leads to yellowing of geranium leaves (dry yellowing): some flower lovers may misunderstand the problem of proper water control of geranium in summer, so let the basin soil dry completely for a long time before watering, causing the geranium leaves to turn yellow and fall off from the bottom up. In severe cases, the petiole drooped and wilted.

Solution: in this case, we need to adjust the watering method and use the principle of alternating dry and wet to water the small sky.

4. Sun exposure leads to yellowing (burning yellow) of geranium leaves: yellowing symptoms are written here.

Geraniums are in a warm and humid environment, and exposure to the sun will cause leaves to turn yellow and die.

Solution: it's best to put it in the shade in summer.

5. Dry air leads to yellowing of geranium leaves: dry air and poor ventilation will lead to withered and yellow branches and leaves.

Solution: transplant and place in a ventilated place.

6. Lack of sunlight leads to yellowing of geranium leaves (lack of light): yellowing and shedding of leaves on the inside of the plant due to lack of light, yellowing of old leaves after germination of new branches and leaves, edema disease and yellowing of leaves caused by heavy water, and great changes have taken place in the environment of potted flowers (such as suddenly moving indoors from outdoors in midsummer or just entering the house in winter).

Solution: because the yellowed leaves also hope to restore their vitality as soon as possible, they will absorb the nutrients accumulated by the plant itself, and it consumes more nutrients than it produces. So we don't have to worry too much, we just need to remove the yellow leaves in time.

7. The high temperature leads to the yellowing of geranium leaves: this is due to the high temperature in summer, which affects the root system to absorb iron from the soil normally, resulting in high temperature, iron deficiency yellow leaves and white leaves. When the iron deficiency is mild, the mesophyll tissue of the tender leaf is light green, and the leaf vein remains green; in severe cases, the tender leaves are all yellow-white, and withered spots appear and gradually scorch and fall off.

Solution: don't worry too much about this situation, you can spray and irrigate the chelated iron solution. Once a week, it can basically return to normal after 3 times. In addition, lowering the ambient temperature, such as moving to a ventilated and cool place or an air-conditioned room, the leaves will slowly return to normal.

8. The low temperature leads to the yellowing of the geranium leaves: the geranium likes to be warm in winter and cool in summer. It can blossom normally when the indoor temperature is kept at 10-15 ℃ every day in winter and the night temperature is above 8 ℃. But the optimum temperature is 15-20 ℃. If the temperature is too low, it will cause the leaves to turn yellow.

Solution: it is best to keep it indoors in winter to maintain the optimal temperature.

9. Excessive fertilization of geranium leads to yellowing of leaves (fat yellow): excessive fertilization or high concentration will cause root burning and rotting, and the reaction on the leaves is that the old leaves are yellowing, the young leaves are thick, shiny and uneven.

Solution: fertilizer control, ploughing and watering are needed at this time. If the fertilizer damage is serious, you should immediately pour the basin, remove part of the old soil, wash the soil block with water, replace it with plain soil without fertilizer, and re-root.

10. Geranium long-term lack of fertilizer leads to yellowing of leaves (lack of fat yellow): pelargonium blossoms diligently, and flowering consumes a lot of nutrients. Spring is the full bloom of small days, they spare no effort to bloom heartily, bringing a lot of happiness and joy to flower friends, if we do not carry out proper topdressing in time, there will be yellow leaves after flowering.

Solution: this situation should first be light and then concentrated and then gradually increase the concentration of fertilizer for topdressing, so as to prevent excessive fertilization from burning seedlings until the color of the leaves returns to normal.

11. Rotten roots cause yellowing of geranium leaves: too much watering leads to rotten roots of geraniums.

Solution: remove the rotten root, sprinkle it with doinling on the root, plant it with new soil, irrigate it with soaking water 3 hours after planting, and spray the leaves with doinling.

12. Diseases and insect pests cause yellowing of geranium leaves: if geranium is infected by fungi, viruses and other pathogens, it will cause a variety of leaf spot disease and gray mold, resulting in local tissue necrosis, loss of green macula or yellow-green mottled, or the whole leaf yellowing and falling off. Damaged by red spiders, white planthoppers and other pests, chlorophyll is destroyed, leaves also appear yellow and white spots, or leaves become yellow and fall off.

Solution: this requires timely spraying according to the causes of diseases and insect pests.

Culture methods of geraniums:

1. Soil: geranium has strong adaptability and can grow in all kinds of soil, but the sandy loam soil rich in humus grows best.

2. Watering: geraniums like dryness, hate dampness, and should not be watered too much in winter. When the soil is wet, the stem is tender, which is not conducive to the sprouting and opening of flower branches. Long-term excessive humidity will cause the plant to grow too much, the position of the flower branch to move up, and the leaves to yellowing and fall off.

3. Sunshine: geraniums need plenty of sunlight during their growing season, so they must be placed in the sun in winter. Lack of light, long stems and leaves, soft pedicels and dysplasia of inflorescences. Buds in low light often fail to bloom and wither ahead of time.

4. Temperature: the geranium likes to be warm in winter and cool in summer. It can blossom normally when the indoor temperature is kept 15 ℃ every day in winter and the temperature at night is above 8 ℃. But the optimum temperature is 15-20 ℃.

5, fertilization: geraniums do not like big fertilizer, too much fertilizer will make geraniums grow too prosperous and not conducive to flowering. In order to bloom luxuriantly, watering dilute book fertilizer water (rotten bean cake water) once every 2 weeks can promote normal flowering by watering 800 times potassium dihydrogen phosphate solution every 7-10 days.

6. Insect pests: geraniums are poorly ventilated and too humid, and are prone to leaf spot and Fusarium wilt. After discovery, pay attention to ventilation, immediately remove sick flowers and leaves to prevent infection, and spray the same amount of Bordeaux solution to prevent and cure. The main pests are red spiders and whitefly, which can be sprayed with 1000 times of omethoate emulsion.

7. Pruning: pruning in order to promote more flowering of the geranium with more branches, it is necessary to pick the heart of the plant many times to promote it to increase branches and budding. After shedding the flowers, cut off the residual flowers at the right time, cut off the too dense and thin branches, so as not to consume too much nutrients, but it is cold in winter and should not be re-cut.

Maintenance of Pelargonium in winter

Geraniums like temperature and light and are afraid of cold. Measures should be taken to prevent cold in winter. The indoor temperature should be kept at 15 ℃-20 ℃ and not less than 10 ℃ at night. In the environment of too low temperature, the plant growth is weak, which is not conducive to flower bud differentiation, resulting in less flowering, or even no flowering. But the environment with temperature higher than 25 ℃ is also disadvantageous to its growth and development. Usually, the pot plant should be placed in front of the sunny window to make it fully receive the light. If the light is not enough, the plant is easy to grow wildly, affecting the formation of flower buds and even causing the formed buds to wither.

Moderate water and fertilizer geraniums are afraid of dampness and drought resistance, so they should be watered appropriately every day, usually every 5-7 days, and keep the basin soil dry and slightly wet. Too much watering will cause leaves to yellowing and fall off, affect flowering, and even cause rotting roots and death. Usually, the foliar surface should be sprayed with clear water to keep the foliar surface clean, which is conducive to photosynthesis. In order to make the pelargonium blossom continuously after winter, sufficient nutrients should be supplied. Dilute liquid fertilizer should be applied every 10 days or so. It can be mixed with bean cake, hoof slices and fishy water and used after fermentation.

Pruning and coring in order to promote more flowering of the more branched geranium, it is necessary to pick the heart of the plant many times to promote it to increase branching and bud pregnancy. After shedding the flowers, cut off the residual flowers at the right time, cut off the too dense and thin branches, so as not to consume too much nutrients, but it is cold in winter and should not be re-cut.

Prevention and control of main diseases of geranium:

1. Leaf spot. In the early stage, small needle-sized, round or irregular brown spots will appear on the leaves, and then gradually expand to dark brown or reddish brown spots, and in severe cases, the whole leaf is covered with disease spots until they dry up and fall off. The stems and branches of the stem are also black, wrinkled and rotten, and even the leaves on the stem wither and die, leaving only a few leaves at the top.

Precautionary measures:

a. Greenhouse cultivation density should not be too large, should pay attention to regular ventilation and light transmission.

b. Avoid watering the plant and avoid splashing water droplets.

c. Avoid cutting cuttings on diseased plants. If diseased leaves and branches are found, they should be cut off and burned.

d. Spray 200 times the same amount of Bordeaux liquid every 2 weeks during the period of high temperature and humidity for 3 consecutive times.

2. Grey mold. The disease is mainly caused by too much watering, which is more serious when it is cold and wet. First harm the flowers, so that the edge color of the petals darkened and withered, too much air humidity will appear gray mold layer, florets kink together, damaged petals fall on the leaves, will also cause the disease of the leaves. There are water-stained brown spots on the leaf surface, which are covered with light gray layers after drying and shrinking.

Prevention and control measures: a. Timely removal of diseased leaves and flowers, watering to avoid feeling on the plant, timely removal of water on leaves and flowers, often pay attention to ventilation and light.

b. In the early stage of the disease, 75% chlorothalonil 500 times liquid was sprayed for 3 times in a row.

Time: 2019-04-12 Click: