Why do the leaves of Alocasia macrorrhizos (giant taro) turn yellow?
1. Spider mites. Gardeners can check whether the surface of the Alocasia macrorrhizos leaves has small white spots, a waxy feel, a rough texture, and no gloss. If so, spider mites are the culprit. To solve this, wash with soapy water twice, with two days between each wash, and that will do it.
2. If the soil is too poor and lacks nutrients, it will also cause the leaves to turn yellow. Therefore, it is very necessary to add nutrients to the soil in time and apply some nitrogen and phosphorus fertilizers and organic fertilizers.
3. Alocasia macrorrhizos is relatively suited to a warm and humid climate. Because winter temperatures are low, leaving it outdoors for a long time makes it very easy for the leaves to suffer cold damage and turn yellow. At this time, place it indoors at a constant temperature and in a spot with sufficient light.
4. A large amount of dust accumulated on the leaves will block the leaves' absorption of light and cause the leaves to turn yellow. Therefore, the leaves should be maintained regularly and can be wiped and washed with clean water.
5. Not watering for a long time will also cause the leaves to turn yellow due to drought. So, always keep the soil moist, and when watering, make sure to water thoroughly, not just wet the surface of the soil.
Reasons why Alocasia macrorrhizos leaves turn yellow
Alocasia macrorrhizos is a common ornamental plant, but if its leaves turn yellow, it will inevitably affect its ornamental value. This is also a issue that many gardeners care about. So, what are the reasons why the leaves of Alocasia macrorrhizos turn yellow? In response to this question, today the editor will tell everyone that the main reasons for Alocasia macrorrhizos leaves turning yellow are caused by the following points:1. Light: insufficient light or no light affects plant growth and morphogenesis. Under such conditions, the internodes of the plant are especially long, and the leaves are underdeveloped and small, causing Alocasia macrorrhizos leaves to turn yellow. Therefore, when growing Alocasia macrorrhizos, it should be given reasonable light.
2. Soil: if the cultivation soil used for Alocasia macrorrhizos is too alkaline or the soil is not changed for a long time, it will lead to a lack of nutrients in the soil, affect the growth of the plant, and then cause the plant's leaves to bend down, turn yellow, and droop. Although Alocasia macrorrhizos does not have high requirements for soil, the fertility of the potting soil medium must be ensured. To solve Alocasia macrorrhizos leaves turning yellow, choose sandy loam or humus loam containing organic matter, change the soil in time, and increase nutrients.
3. Watering: Alocasia macrorrhizos has a relatively large water requirement. During the growing season, it should be kept moist rather than dry. During the winter dormant period, watering should be controlled as much as possible. Pay attention to the method when watering, because improper watering can easily cause Alocasia macrorrhizos leaves to turn yellow.
4. Ventilation environment: if Alocasia macrorrhizos is placed in a poorly ventilated environment for a long time, Alocasia macrorrhizos leaves will turn yellow because of “poor breathing.”
5. Pests and diseases: if Alocasia macrorrhizos has pests or diseases, it can also cause the leaves to turn yellow. The main cause of Alocasia macrorrhizos leaves turning yellow is spider mites. Spider mites like to suck sap on the underside of the leaves. After being damaged, the leaves turn yellow, many small white spots appear, and soon they wither, turn yellow, and fall off. They often breed in high-temperature and low-humidity environments. Pay attention to prevention and control.
6. Cleaning of the leaf surface: leaves are the main site for plant photosynthesis. If the leaf surface is not sprayed and cleaned for a long time, dust will accumulate, which will hinder plant photosynthesis, make the plant lack nutrients, and cause Alocasia macrorrhizos leaves to turn yellow.
7. Weather: because Alocasia macrorrhizos is a tropical plant, it is easy for it to catch cold when the temperature is low in winter. If the temperature of the growing environment is not changed in time, the root system will suffer cold damage, causing Alocasia macrorrhizos leaves to turn yellow. In addition, after winter, if Alocasia macrorrhizos is rushed out of the room and placed in a warm place to bask in the sun, it will temporarily be unable to adapt to the sudden change in climate, which will also cause Alocasia macrorrhizos leaves to turn yellow.
The above points are the reasons why Alocasia macrorrhizos leaves turn yellow. When this phenomenon occurs, it is necessary to treat the cause reasonably so that the problem can be solved in time.
What to do if Alocasia macrorrhizos leaves turn yellow: causes and prevention methods for Alocasia macrorrhizos leaves turning yellow
The ornamental value of Alocasia macrorrhizos lies mostly in its lush, verdant leaves. When watered or when air humidity is high, water droplets will drip from the edges of the leaves, which is very likable. Once Alocasia macrorrhizos shows bent leaves, yellow leaves, or leaves gathering and drooping, the overall form of Alocasia macrorrhizos will be affected, thereby affecting its ornamental value. Therefore, it is necessary to find out in time the reasons causing Alocasia macrorrhizos leaves to turn yellow and treat the cause.
Reasons why Alocasia macrorrhizos leaves turn yellow
The reasons causing Alocasia macrorrhizos leaves to turn yellow or droop can be roughly divided into the following aspects:
1. Effect of light.
Placing Alocasia macrorrhizos in a living room, bedroom, or other place lacking light for a long time will, due to insufficient light, affect the plant's photosynthesis and thereby affect the plant's life activities. Insufficient light or no light affects plant growth and morphogenesis. Under such conditions, the internodes of the plant are especially long, and the leaves are underdeveloped and small, lacking chlorophyll and appearing yellow.
2. Improper watering.
Alocasia macrorrhizos has a relatively large water requirement. During the growing season, it should be kept moist rather than dry. During the winter dormant period, watering should be controlled as much as possible. Pay attention to the method when watering, because improper watering can easily cause the leaves to turn yellow. One wrong watering method is watering “halfway,” that is, not watering thoroughly, without watering until water seeps out from the bottom of the Alocasia macrorrhizos pot. This watering method cannot meet the water requirement of Alocasia macrorrhizos and easily causes the ends of the root system to lack water for a long time, resulting in yellow leaves. Another watering mistake is watering without a regular pattern, watering once whenever one thinks of it, causing the potting soil of Alocasia macrorrhizos to remain too wet or too dry for a long time, which is unfavorable to its growth.
3. Unqualified soil conditions.
If the cultivation soil used for Alocasia macrorrhizos is too alkaline or the soil is not changed for a long time, it will lead to a lack of nutrients in the soil, affect the growth of the plant, and then cause the plant's leaves to bend down, turn yellow, and droop.
4. Weather reasons.
Alocasia macrorrhizos is a tropical plant. When the temperature is low in winter, it is easy for it to catch cold. If the temperature of the growing environment is not changed in time, the root system will suffer cold damage, causing the leaves to turn yellow. In addition, after winter, if Alocasia macrorrhizos is rushed out of the room and placed in a warm place to bask in the sun, it will temporarily be unable to adapt to the sudden change in climate, which will also cause the leaves to turn yellow.
5. Ventilation environment.
If Alocasia macrorrhizos is placed in a poorly ventilated environment for a long time, its leaves will turn yellow because of “poor breathing.”
6. Cleaning of the leaf surface.
Leaves are the main site for plant photosynthesis. If the leaf surface is not sprayed and cleaned for a long time, dust will accumulate, which will hinder plant photosynthesis, make the plant lack nutrients, and cause the leaves to turn yellow.
7. Effect of diseases.
The main cause of leaves turning yellow is spider mites. Spider mites like to suck sap on the underside of the leaves. After being damaged, the leaves turn yellow, many small white spots appear, and soon they wither, turn yellow, and fall off. They often breed in high-temperature and low-humidity environments. Pay attention to prevention and control.
8. Human-caused damage.
Human-caused damage to the leaves and branches of the plant will cause the plant's transport system to be damaged, thereby preventing nutrients from reaching the leaves and causing the leaves to turn yellow.
How to prevent Alocasia macrorrhizos leaves from turning yellow
To prevent and control Alocasia macrorrhizos leaves turning yellow, start from the causes and treat the cause.
1. Reasonable light and ventilation
Give Alocasia macrorrhizos reasonable light conditions. Alocasia macrorrhizos likes a semi-shady environment. When caring for it, pay attention to shading, but remember not to place it in a dark environment for a long time. In addition, also pay attention to the ventilation of the environment and keep the air flowing.
2. Watering requirements for Alocasia macrorrhizos
Alocasia macrorrhizos has a large water requirement. Water when the soil looks dry, and water thoroughly at one time until water flows out from the bottom of the pot. Watering should be regular; do not let the potting soil remain too dry or too wet for a long time. When watering, also use a watering can to clean the leaves and keep them clean, and by the way you can also see the water roll off the leaves.
3. Soil requirements for Alocasia macrorrhizos
Alocasia macrorrhizos does not have high requirements for soil, but the fertility of the potting soil medium must be ensured. Choose sandy loam or humus loam containing organic matter, change the soil in time, and increase nutrients. To increase the plant's own resistance, do not use only nitrogen and phosphorus fertilizers. Use them alternately with organic fertilizers. Applying a little ferrous sulfate will make the leaves larger and greener.
4. Maintain a suitable temperature
Keep the living environment of Alocasia macrorrhizos warm and humid. When the weather is cold in winter, move it indoors in time; slowly change the living environment of Alocasia macrorrhizos so that it adapts to changes in environmental temperature. Remember that Alocasia macrorrhizos must not be placed in an environment where the temperature fluctuates between high and low.
5. Avoid human-caused damage
Prevent human-caused damage to Alocasia macrorrhizos. The sap of Alocasia macrorrhizos is toxic, so try to avoid contact with its body as much as possible. When spider mites appear on the plant, spray with 40% dimethoate emulsifiable concentrate at 1000 times dilution or 80% dichlorvos at 1000-1500 times dilution.