What are the causes of poinsettia leaf drop and the solutions

Livestock Farming Jan 1, 1970 0 views

Poinsettia

Poinsettia is both a flowering plant and a foliage plant. Its leaves are emerald green and its flowers are Chinese red, giving a very festive feel, so poinsettias are used to decorate the scene at some large celebrations. However, when poinsettia care is not thorough, leaf drop can occur, and if this is not taken seriously it will seriously affect its ornamental value. So what should be done when a poinsettia drops its leaves?

1. Too much light

Poinsettia must absolutely avoid direct strong light in summer. If the sunlight is too strong and ventilation is poor, it is easy for the poinsettia to drop leaves due to high temperature and dryness.

Solution: In summer, poinsettia potted plants should be placed in a well-ventilated location, with a distance of 50 cm between pots. The ground should be sprayed with water frequently, which can increase air humidity and effectively control leaf drop caused by high temperature and dryness.

2. Temperature too low

Poinsettia likes a warm, humid and cool climate and is not cold-tolerant. The suitable growth humidity is 15-20°C. In winter, keep the nighttime temperature above 15°C and it must not fall below 5°C, otherwise the leaves are prone to falling. If a window is opened once in winter and cold wind blows in, it can also cause the plant to drop a large number of leaves.

Solution: Too low a temperature is the main cause of poinsettia leaf drop. For this reason, in winter it is best to keep the poinsettia in a relatively high and stable temperature environment for care.

3. Too much watering

Poinsettia is afraid of both dryness and waterlogging. If the potting soil is too wet and the plant canopy is too dense, photosynthesis cannot proceed well, causing malnutrition and leaf drop.

Solution: Poinsettia should be watered appropriately, not too much. If there is heavy rain, drain the water, or move the potted plant indoors before the rain.

4. Too little watering

Poinsettia likes moisture. If it is too dry and exposed to strong sun, the plant will suffer physiological water shortage, and the leaves will curl and drop in large numbers.

Solution: In spring, water poinsettia once every 2 days. In summer, when branches and leaves are lush and growth is fast, the amount of watering should be greater and sufficient water should be provided.

Poinsettia

5. Improper fertilizing

Poinsettia likes fertilizer. During the growing period it needs more nitrogen fertilizer. If nitrogen fertilizer is insufficient, the lower leaves of the plant will fall off.

Solution: In addition to the base fertilizer applied when potting, within one month after pinching, apply once every 7 days or so a diluted fermented cake fertilizer water. Do not apply too much. During the flowering period, do not apply too much fertilizer, otherwise the leaf bracts will become scorched. Before moving indoors in winter, applying 40% fermented human feces and urine is sufficient.

6. Pests and diseases

When poinsettia is attacked by red spider mites, whiteflies, black spot disease, leaf drop disease, anthracnose and so on, the plant often drops leaves. Air pollution: if there is a coal stove indoors, the gas produced when coal burns affects the growth of the flowers, and over time the leaves will also fall off.

7. Metabolism

As the saying goes, "autumn wind brings fallen leaves." In autumn, poinsettia, like other plants, will also drop leaves and enter dormancy. There is no need to worry about this situation. This is a metabolic response of the plant, just like people losing hair in large amounts when the seasons change.

Usually, by doing basic care well, giving reasonable light, providing water and fertilizer at the right time, and doing a good job of disease and pest prevention, there will basically not be any major problems. Poinsettia is relatively easy to grow. Gardeners just need to put in a little effort and that is enough!

What to do when poinsettia drops leaves: analysis of common causes and solutions

Poinsettia is a very unique ornamental plant. The red leaves at the top look very festive, so many people choose one to take home to decorate their homes during festivals. However, during cultivation, poinsettia may drop leaves. So what should be done when poinsettia drops leaves? Below, the editor tells everyone the causes of poinsettia leaf drop and the solutions.

What to do when poinsettia drops leaves

Cause: 1. Too much light

Cause: 2. Temperature too low

Cause: 3. Too much watering

Poinsettia is afraid of both dryness and waterlogging. If the potting soil is too wet and the plant canopy is too dense, photosynthesis cannot proceed well, causing malnutrition and leaf drop.

Solution: Poinsettia should be watered appropriately, not too much. If there is heavy rain, drain the water, or move the potted plant indoors before the rain.

Cause: 4. Too little watering

Poinsettia likes moisture. If it is too dry and exposed to strong sun, the plant will suffer physiological water shortage, and the leaves will curl and drop in large numbers.

Cause: 5. Improper fertilizing

Poinsettia likes fertilizer. During the growing period it needs more nitrogen fertilizer. If nitrogen fertilizer is insufficient, the lower leaves of the plant will fall off.

What to do when poinsettia leaves turn yellow

1. Control watering

Yellow leaves are mostly caused by too much watering. Water accumulation in the pot makes it difficult for the poinsettia roots to access enough oxygen, and they are suffocated into yellowing. Therefore, from the moment yellow leaves are discovered, reduce the amount of watering, and do not water again until the potting soil appears dry and pale.

2. Cut off rotten roots

Yellow leaves on poinsettia are generally only a surface sign; root rot is the internal cause. Therefore, appropriately turn out the poinsettia root system to observe it. If rotten roots are found, cut them off in time to prevent bacteria from continuing to infect other parts.

3. Loosen the soil

Use a small shovel to loosen the potting soil, increasing water evaporation and oxygen infiltration. This is absolutely beneficial for improving the yellow-leaf symptoms of poinsettia.

4. Increase light

Although poinsettia is a short-day plant, if it does not receive light for a long time, the leaves will not only fail to stay green but will also easily turn yellow. The correct approach is to immediately move the potted plant to a place with sufficient light to promote photosynthesis.

5. Raise room temperature

In winter, keep the room temperature above 15°C and turn on more heating, which is beneficial to the growth of poinsettia, and the yellow-leaf symptoms will also be greatly reduced.

Poinsettia leaf drop and yellowing leaves are common problems in poinsettia care. This requires finding the causes and applying corresponding solutions. Poinsettia is a plant grown for both foliage and flowers. If the leaves drop, it will affect the ornamental value of the poinsettia, so everyone should pay attention to care.

What to do when poinsettia leaves are not red: causes of leaves not turning red and solutions

Poinsettia is deeply loved by consumers because of its bright flower color, long flowering period, and moderate price. But many gardeners have told the editor that poinsettia leaves always cannot be grown red. What is the reason? Below, follow the editor of wed114 wedding website to take a look at what to do when poinsettia leaves are not red, understand the causes of leaves not turning red and the solutions, and also an introduction to methods for growing poinsettia.

Introduction to poinsettia

Poinsettia is a plant of the genus Euphorbia in the family Euphorbiaceae, also known as Christmas flower. It is a red flower used for decoration at Christmas. It originated in a certain color-changing foliage plant in the Taxco region of Mexico.

Poinsettia is usually 60 cm to 3 m tall, and its dark green leaves are about 7 to 16 cm long. Its topmost leaves are fiery red, red, or white, so they are often mistaken for flowers, while the true flowers are in the middle of the leaf cluster. The flowering period can last from December to February of the following year. The flowering period coincides with Christmas and New Year's Day, making it very suitable for a festive holiday atmosphere.

Poinsettia can be used as a medicinal plant and has the effects of promoting blood circulation and resolving phlegm, and setting bones and reducing swelling.

What to do when poinsettia leaves are not red

Cause 1: Long-term lack of light

Solution: With insufficient light, poinsettia is not only unfavorable for growth but also prone to illness. So not seeing red bracts is still a small problem. It is lucky that symptoms such as yellow leaves and root rot have not appeared. Hurry and move your poinsettia to a place with sufficient sunlight. Its red bracts will believe soon appear.

Cause 2: Flowering period has not arrived

Solution: The flowering period of poinsettia can last from December to February of the following year. If its flowering period has not yet arrived, that is, it is still in the growing period, green leaves may be constantly sprouting, so gardeners naturally see relatively fewer red bracts.

Cause 3: Insufficient fertilizing

Solution: Insufficient fertilizing is fatal to the growth of poinsettia. Poinsettias lacking fertilizer are often short and weak. Did Mom Network Encyclopedia say it right? Hurry and apply some special plant nutritional fertilizer to it. This is very good nutrition for it to sprout and grow red bracts.

How to grow poinsettia

Many people do not know much about how to grow poinsettia. Not long after buying a poinsettia home, the leaves wither. Below, the editor introduces the cultivation methods for poinsettia.

1. Poinsettia is afraid of both drought and waterlogging. Therefore, each watering must be thorough, and after the potting soil appears dry, water promptly again, and frequently spray water on the leaf surface. During winter cultivation, water should be controlled appropriately.

2. Poinsettia has relatively high requirements for temperature, humidity, light and so on. If the temperature is too low or too high, light is insufficient, ventilation is poor, or water and fertilizer are improper, the leaves will turn yellow and fall off, and it will not bloom. Poinsettia is a short-day plant. During the day, light time must be ensured, while at night it must be kept absolutely away from light (including artificial light). This is beneficial for forming flower buds.

3. Poinsettia likes fertilizer. From August to October, mainly use phosphorus fertilizer, applying fertilizer once every 10 days. Alum fertilizer water can also be used to promote the growth of bracts.

4. For potted poinsettia, the plant height should preferably be controlled at 40-50 cm. Appropriate methods such as withholding water, withholding fertilizer, bending branches, and topping can be used to control its height.

5. For potted poinsettia, 2 parts garden soil, 2 parts leaf mold, and 1 part compost can be mixed as the substrate.

Potted care of poinsettia

To care for poinsettia, do a good job in fertilizer and water management during the growing period, control heading, and keep warm and prevent cold damage.

Watering should be even, preventing excessive dryness or wetness, otherwise the lower leaves of the plant will turn yellow and fall off, commonly known as "bare legs," or the branches will grow unevenly. During the plum rain season and summer showers, prevent water accumulation in the pot. After rain, tilt the pot promptly to pour out water, or move it indoors together with the pot before rain. In hot summer weather, water demand is high. Water thoroughly with clean water every morning, and observe in the evening. If the potting soil is found to be dry, water once more, and this time the amount can be smaller. In spring and autumn, generally water once every 1-2 days, depending on the weather and whether the potting soil is dry or wet.

Cultivation and fertilizing work cannot be ignored. Two to three weeks after potting, a small bamboo piece can be used to loosen the potting soil so that soil air can circulate, and then some liquid fertilizer can be applied. Either 20% decomposed human feces and urine or soybean water can be used. From mid-August to October, the number of fertilizer applications needs to be increased, about once every 10 days, and appropriately apply several kinds of flower fertilizer, with the concentration also slightly stronger, using 30% decomposed chicken, duck, and pigeon manure water. This can promote sufficient growth when flower buds are forming.

After potting, poinsettia grows relatively fast, so heading must be controlled; otherwise the branches will grow too tall, easily fall over in strong wind, and affect the beauty of the posture. Heading can be divided into two types according to need: straight heading or scenic training. In the straight heading form, after the last heading in June, let the branches keep growing, and they can grow into a large plant 60-70 cm tall. For scenic training, when the headed growth reaches 10-15 cm, cut lead wire into 15-20 cm sections, bend the upper end into a hook shape, insert the lower end into the potting soil, and hook each branch from top to bottom to the pot surface with the upper end. After about 10 days, when the branches have continued to grow about 15 cm, guide the branches horizontally along the edge of the pot, and after another 10 days, guide the branches that have reached the pot edge upward. From mid-September to late October, use 30-40 cm long thin bamboo sticks to tie each flower head. If at flowering time the branches are uneven in height, arrange them: tie the tall ones downward and pull the low ones upward. This method takes a lot of work, but it can make the potted flowers neat. Many dwarf poinsettia varieties introduced from abroad can achieve the goal of short plants, large flowers, and neat flower heads simply through heading control.

Every year in mid-October, before Frost's Descent, poinsettia should be moved indoors for care. Too late and it will suffer cold damage; too early and the high indoor temperature will cause the plant to grow leggy. When first moved indoors, place it in a ventilated place; by mid-October, place it in a warm, sunny place facing south, no longer exposed to cold wind, so as to prevent leaves from turning yellow and falling off. Generally in early to mid-December, the top leaves of poinsettia turn red and, set off by the green leaves, appear especially red and brilliant.

Disease control of poinsettia

I. Diseases

These mainly include stem rot and gray mold caused by fungi, and leaf spot caused by bacteria. In addition to regularly spraying fungicides, auxiliary work such as ventilation and air exchange and reducing humidity should also be done well in the greenhouse to reduce pathogens. Tools should be disinfected promptly to prevent cross-infection, and diseased plants should be cleaned up in time to reduce sources of infection. In winter, sulfur fumigators or sulfur-containing smoke bombs can be used to kill fungal spores in the air.

During greenhouse cultivation, poinsettia is susceptible to diseases and pests such as gray mold, root rot, stem rot, and leaf spot, and there have been many targeted studies at home and abroad.

1. Gray mold

It mainly occurs in winter, which is exactly the flowering season of poinsettia. Once there is continuous cloudy rain, dampness, and no sunlight, it often gets out of control and can harm poinsettia inflorescences, bracts, leaves, and branches. Generally, water-soaked lesions first appear from the inflorescence. Afterward, the lesion is covered with a layer of pathogen conidia, and the pathogen continues to spread to the bracts. In the early stage on the bracts, water-soaked discolored spots appear, then gradually expand into an irregular shape. The pathogen then spreads to the branches, producing yellow-brown to brown lesions on the branches. In the later stage, the lesions clearly sink downward and appear dark brown. In severe cases, the lesion area becomes dry and withered, completely losing ornamental value. The pathogen is Botrytis. The pathogen is almost everywhere in the entire greenhouse. It can survive on dead plant tissues or other organic matter and has a wide host range. It can survive at temperatures of 0-38°C. As long as there is moisture, it exists. If the greenhouse is too humid, cold and cloudy, and short of light, after 1-2 days the pathogen produces a large number of conidia that float in the air and begin to infect plant tissues.

2. Root rot and stem rot

It can infect adult plants and can also infect during the seedling bed stage, causing serious losses. It generally occurs more severely in high-temperature seasons, and is also extremely likely to occur when the cultivation soil has high water content. In the early stage, the plant shows wilting. At this time, if the stem base is examined, a light brown constriction can be seen, but the infected plant shows no rot or hydrolysis. Later, the lesions gradually spread upward, and the wilting gradually becomes more serious. The stem lesions are slightly sunken and yellow-brown. In the later stage, the tissue at the lesion disintegrates, causing the plant to wither and die due to severe water shortage. Sometimes the whole plant becomes water-soaked and yellowed, eventually rotting and dying. White mycelium can be seen near the ground, and in severe cases it can spread to the cultivation soil. When the roots are diseased, root rot often occurs. In the early stage it affects the normal growth of the plant, and in severe cases it leads to death. The pathogens are mainly Phytophthora, Rhizoctonia, Pythium, etc. When rooted cuttings are potted, they are most susceptible to Rhizoctonia, especially when the stem is injured or fertilizer salts accumulate on the medium surface;

3. Pythium

It appears when poinsettia is an adult plant. It may already have invaded during cuttings. When the environment is suitable for reproduction, it worsens, causing root rot and death. High temperature and excessive irrigation (adverse conditions) can cause Phytophthora damage.

4. Leaf spot

It mainly occurs more severely in spring and summer, and the lesions mostly begin on old leaves. In the early stage, purple-red to brown small spots appear on the leaves, and the lesions are nearly round to irregular. Later, the lesions gradually expand, and most lesions can merge with each other to form one large lesion. In the later stage, the center of the lesion gradually turns gray-brown. In severe cases, the lesion tissue becomes gangrenous, causing the leaves to twist and dry up. The pathogen is Cercospora.puleherrimaeTherp., spread by rain and wind, invading through leaf margins or wounds.

II. Pests

The most common is whitefly, which can be controlled by spraying insecticide or drenching the roots. Taking advantage of the phototaxis of whitefly, yellow sticky insect boards coated with machine oil can be placed in the greenhouse to trap and kill them. In addition, note that whitefly generally sucks sap on the underside of young leaves, and light-colored leaves are more likely to attract whitefly damage. The main pests of poinsettia are whitefly, spider mites, thrips, and so on.

1. Whitefly

Adult and larval whiteflies like dense, shaded environments. They cluster on the underside of upper poinsettia leaves and suck sap with piercing-sucking mouthparts, causing leaves to fade or develop chlorotic spots, affecting photosynthesis, and leading to poor plant growth. The honeydew excreted by the insect bodies often causes sooty mold. Adults are attracted to yellow. Emergence begins at 6 a.m., with the greatest emergence from 7-8 a.m. and the lowest in the evening. Whiteflies are most fragile as newly mobile larvae, followed by newly emerged adults, and are sensitive to pesticides, making those stages suitable for spraying control. Whiteflies generally occur in large numbers under high temperature and low humidity, with the peak period from late September to late November. The optimal control period is late September, and the spraying time is from 6-10 a.m.

2. Spider mites

Spider mites, also known as red spiders, are common pests in greenhouses. More than 20 generations occur throughout the year. They occur severely under conditions of higher temperature and little rain. March to June and September to November are peak occurrence periods. Mites or nymphs all prefer to inhabit the underside of old leaves. Damaged leaves have yellow spots. Inspecting the leaf underside can reveal insect bodies, eggs, webs, secretions, and other debris. When they occur in large numbers and form webs, they cause plant growth to stagnate, leaves to dry up and fall off, and the plant to die.

3. Thrips

Thrips are only about 1-2 mm long and can be found causing damage on the leaves or flowers of almost all greenhouse-cultivated plants. But under normal circumstances, the damage to poinsettia is not very serious. Adults and nymphs are light yellow or orange-yellow and harm plants with rasping-sucking mouthparts. Damaged parts include buds, leaves, flowers, and so on, with young leaves and new shoots suffering the most severe damage, causing poor plant development. White markings on both sides of the leaf midrib can be used to identify the damage characteristics of thrips. Leaf damage causes white or brown markings, and in severe cases causes leaf twisting and deformity. Flower damage causes deformation. Yellow sticky insect paper is effective against adult thrips, but blue and white sticky insect paper works even better.

4. Whitefly

The key to controlling whitefly is to avoid the production of large populations. Adult whiteflies are attracted to bright yellow, so yellow sticky insect paper is very useful for monitoring. There are many drugs for controlling whitefly in various places, such as "Pujiling," "High-Efficiency Dachen," and so on, all of which can be tried. Note here that before using a new drug on a large scale, a phytotoxicity test must first be done, and only after confirming that the dose used will not cause phytotoxicity to the plants should it be used on a large scale.

What are the causes of poinsettia leaf drop and the solutions

What to do when poinsettia drops leaves: analysis of common causes and solutions

What to do when poinsettia leaves are not red: causes of leaves not turning red and solutions

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