Since poinsettias are typically known for their red and green colors, it may be difficult to understand why they would turn yellow. When this happens, there is usually a problem with the growth or soil that needs to be addressed. Let’s find out more about this so you can help your poinsettia keep its red and green color.
Why Is My Poinsettia Turning Yellow?
The poinsettia is turning yellow due to an environmental stressor or too much water, but it may also be caused by not enough light.
I will now go into more depth on each of these causes. By the end, you should have a better idea of what to do when your poinsettia turns yellow.
Yellowing Poinsettia from Overwatering
The first cause for a yellowing poinsettia is overwatering. This happens when there is too much water in the soil or growing medium, which can be caused by not enough drainage holes to allow excess water to escape from the pot.
This causes two problems: one being that your plant will continue to take up more and more water, which can lead to root rot or fungal diseases. The other is that without proper drainage, the roots are unable to get oxygen and will suffocate.
Since this is caused by overwatering, you should reduce the amount of water given to your poinsettia immediately! Let it dry out a bit before giving it more water, and make sure to provide good drainage.
It‘s recommended to only add more water when the top inch of soil is dry. You can test this by sticking your finger into the soil. Alternatively, you can use a moisture meter to test the soil.
If root rot is already present, then time is of the essence! It’s important to act quickly if you want to save your poinsettia from this condition. The first step is to remove all the soil and growing medium you can from the pot.
Next, prune all rotten roots and discard them away from all plants. Finally, repot your poinsettia into fresh soil/growing medium with good drainage holes so there is no chance of overwatering again.
Yellowing Poinsettia from Too Little Sunlight
The next cause of a yellowing poinsettia is not enough sunlight. This happens when your plant isn’t getting enough light, which can lead to poor growth and a lack of flowers.
This causes two problems: one being that your plant will continue to grow more and more slowly, which can lead to stunted growth. The other is that without proper light, the leaves may yellow or drop off entirely since there is no chlorophyll production.
Since this is caused by a lack of sunlight, you should increase how much sun your poinsettia receives immediately! Make sure to rotate the pot every day so that all sides receive equal sunlight over time.
Make sure there are no objects or other plants blocking your poinsettia from receiving the light it needs. This is a common mistake that many plant carers make.
A good idea is to use artificial grow lights (Amazon link) to create a more consistent amount of sunlight. This way, your plant will receive light as soon as it wakes up and can be used during the night to help with flowering or dormancy periods.
Yellowing Poinsettia from Environmental Stress
The final cause for yellowing poinsettia is environmental stress. This happens when there are one or more outside sources that may not be ideal for the plant, which can lead to poor growth and a lack of flowers.
This is typically caused by the wrong environment, so it’s important to understand what your poinsettia needs.
This means that you should not place them near heaters, vents, fireplaces, or any other sources of heat that can dry them out and put them into a state of shock. When it starts to get cold outside, you should bring your poinsettia inside where it will be warm and well-lit.
Another way to cause stress is to repot your plant. You see, many of us think we are helping our plants when we give them a new home, but this is often a mistake. As such, only repot when necessary.
Yellowing Poinsettia Leaves FAQ
Poinsettia plants require unique care to thrive. As such, I will now answer some of the questions I get asked on a frequent basis (about the plant’s leaves).
Should I cut yellow leaves off my poinsettia?
Yes, you should use a pair of sterilized scissors to cut off any yellow leaves. Doing this will encourage new, healthy growth.
Will the yellow leaves on my poinsettia spread to other plants?
Only if your poinsettia has a fungal disease or pest infestation. Otherwise, there is no reason to be concerned.
Does the type of water I give to my poinsettia matter?
Yes, certain types of water may lead to root rot or other problems. As such, it’s important that you only use distilled or filtered water when watering your poinsettia.
Will too little light cause my poinsettia to turn yellow?
Yes, if your poinsettia isn’t receiving the right amount of light then it will begin to grow slowly and its leaves may turn yellow or drop off.
Will too much water cause my poinsettia to turn yellow?
Yes, if your poinsettia is overwatered then the roots will begin to rot and you may see yellow leaves or brown spots. This is a sign that the root system is dying and needs to be cut back immediately.
Will yellow poinsettia leaves turn green again?
No, it is very unlikely for your poinsettia’s leaves to return back to green. However, new growth may appear if you give your plant the care it needs to thrive. This means that you should place it in the best environment and give it plenty of sunlight.
In conclusion, your poinsettia should not turn yellow if it is receiving the appropriate amount of sunlight and water. The other cause for a yellowing poinsettia plant would be environmental stress, such as the wrong conditions, getting cold, or repotting.
I hope his article has helped you to understand why your poinsettia is turning yellow and what you can do to fix it. If this isn’t the case, feel free to contact me for more help. I would be happy to offer my assistance in any way that I can!
Tim is an avid gardener from the UK. He was the founder of PlantCarer.com from 2021 to Sep 2023. He sold PlantCarer.com to Aaron. He has since started his own business called Seed To Supper, which provides new gardeners all the materials you need in a box (pots, seeds, compost and instructions) to grow your own delicious and nutritious vegetables and herbs from start to finish – no garden required.