Poinsettia leaves rolled up and turned yellow may be caused by too low temperature, too much light, improper watering, and too small flower pots, which need to be adjusted appropriately according to the growth state of the plants. The plant should be placed in an appropriate position, watered and given light. When the plant grows up, it is necessary to replace the flowerpot and fertilize in time to ensure that the plant can grow normally.
Poor poinsettia leaves roll up and become yellow, and poinsettia has poor cold resistance. The temperature should be controlled at about 24 degrees in spring and summer, and about 15 degrees in autumn and winter. If the temperature of the plant is low during the growth period, the growth will be restricted, the leaves will not grow normally, and it will curl yellow. If the temperature in winter is lower than 5 degrees, the plants will be frostbite.
The intense light will make the leaves of poinsettia roll up and turn yellow, and the intense light will evaporate the leaves' moisture, damage the tissues of the leaves, and make the leaves dry and curled. After the leaf tissue is damaged, the leaves cannot normally absorb nutrients and water, and the lack of nutrients will slowly turn yellow and fall off. Placing the plant under strong light for a long time can make the plant die.
Poinsettia is afraid of flooding. It doesn't need much water during growth, just water it properly. If watering is too little, the plant lacks water to maintain growth, resulting in the lack of water on the branches and leaves, and the phenomenon of leaf shrinkage and yellowing will occur. Excessive watering will cause a large amount of water to accumulate on the bottom of the pot, which will cause the roots of the plant to rot, the roots cannot properly transport nutrients and water, and the leaves will shrink and turn yellow.
During the cultivation of poinsettia, pots need to be changed according to the growth state. If the pots are not changed in time, it will affect the extension and growth of the roots, damage the roots, and affect the roots' absorption of nutrients. In the state of lack of nutrition, the plant will appear weak and dry yellow. If the flower pot is not replaced for a long time, it will cause the leaves to shrink and yellow continuously, which will affect the plant growth.