Yucca leaves will turn yellow as a sign of stress due to changes in their living conditions that are less than ideal. One of the most common causes of yellowing yucca leaves is overwatering. Yuccas do not require frequent watering because they are succulents that can tolerate drought-like conditions. If you overwater them or plant them in poor-draining soil, yellowing leaves will be one of the symptoms.
Other causes of yellowing yucca leaves are underwatering, insufficient light, transplant stress and pests.
In this article, we will discuss the causes of yellowing yucca leaves and how to remedy each one.
Why are my yucca leaves turning yellow?
Overwatering
The most common cause of yellowing yucca leaves is overwatering. This happens when you water the plant too frequently, grow it in pots without drainage holes at the bottom, use a tray or saucer to catch the excess water under the pot and fail to empty it, or if the soil is too rich and retains too much moisture.
Yucca plants are native to the driest areas of the Caribbean and Mexico. They are adapted to living in sandy soil with little to no rain. They are also drought-resistant.
If your yucca’s roots are soaking in boggy soil for long periods of time, it can lead to stress and yellow leaves. Waterlogged yucca roots are also more susceptible to disease and pests.
You can save your overwatered yucca plant by essentially simulating the living conditions the plant might have in its natural habitat. Start by lessening the frequency and amount of water you give your plant.
The easiest way to figure out if your yucca plant needs to be watered is by touching the soil. If the top two inches of soil are dry, you can water it. The frequency of watering yucca plants is typically between 10 to 14 days, but factors like sunlight, humidity and temperature also affect this. Just be prepared to adjust according to what your plant prefers. Grow your yucca plants in pots with drainage holes at the bottom. This will allow any excess water to flow out so that the soil does not become saturated with water.
Use succulent soil mix instead of normal potting soil. Normal potting soil is too rich and retains water too well for the yucca to have enough time to dry its roots. You can make your own succulent mix at home by mixing one part potting soil, one part perlite and one part sand. The perlite and sand will make the soil porous, well-draining and airy.
Not all overwatered yucca plants can make a full recovery; some may have root rot that has reached the stem and you are better off cutting some healthy leaves off for propagation.
Underwatering
Another reason for your yucca plant turning yellow is underwatering. Underwatering is less likely than overwatering, but it is still very much possible. Yuccas can become underwatered if they have been neglected, or if the weather changes and they are exposed to a hot climate with low humidity. The yucca’s roots may have a hard time taking in water because it is evaporating too quickly.
Even if yuccas are drought-resistant, they still need a good soak once in a while. The correct way to water a yucca plant is to soak the soil with enough water that excess water flows out of the drainage holes at the bottom of the pot. This ensures that the soil is wet all the way to the bottom.
If the plant has been left without water for too long, it is best to place the pot in a tray with water for two hours, so that the plant can absorb the water instead of just getting soaked. After the plant has recovered, establish a watering schedule that suits your plant.
Insufficient light
If the yucca plant does not get enough direct sunlight, the leaves will turn yellow. In its natural habitat, yucca plants thrive under the sun. If you give it too much shade, the leaves will turn yellow and droop because of stress. In the winter, you need to take the plant indoors and near a south-facing window so that it gets all the light it needs despite the season. But take note that even if you place the plant in a spot that gets sun for a certain part of the day, this does not mean it is getting the correct number of hours of sunlight.
When a yucca thinks that it is not getting enough light, it will choose to let go of its bottom leaves and prioritize the leaves at the top. This is why the leaves at the bottom will turn yellow and wilt.
The wilted leaves at the bottom cannot recover, so just prune them off, but the rest of the plant should be able to make a full recovery especially in the spring and summer when it can get all the light it needs.
Keep in mind that yucca plants can get quite tall and the upper leaves can get blocked from the sunlight, depending on the angle of the light when it enters the window. Make sure you place the plant in a location where all the leaves get exposed to light. If that is difficult, you can just rotate the plant every few days so that every leaf gets its fair share.
Even if you give the plant enough light, its recovery may not be immediately apparent. Yuccas are slow-growing, so give them time to recover.
Transplant shock
Yucca leaves can also turn yellow when you have just brought them home from the nursery. This is the plant’s reaction to the sudden changes in living conditions when it is moved.
A plant that was grown in a nursery greenhouse was in the most ideal conditions. The moment you bring it home, it will go into transplant shock because of the disparity between the growing conditions in the nursery and those of your home. A greenhouse has consistent temperature, light and water. In your home, the temperatures are changing, the light is not consistent and the watering schedule is most likely different from the one it was used to in the greenhouse.
As long as you do your best to give the plant consistent and ideal living conditions, the transplant shock should be temporary and the plant will soon adjust to your home. Do not be alarmed if some leaves die back, because new growth will replace them. Just prune the dying and dead leaves and the plant should be fine.
Pests
Bugs like spider mites, scale insects and mealybugs can feed on your yucca plant and drain its moisture. If your plant becomes infested, its leaflets and fronds will turn yellow.
These insects are more likely to attack your yucca if it is kept indoors. If they are not caught in the early stages of the infestation, they will proliferate and spread from leaf to leaf until the entire plant has been taken over. The mouths of these insects pierce and deplete the plant, further accelerating the yellowing.
You can use a pesticide to remove the bugs, but you can also just use alcohol on a cotton ball to wipe down each leaf. Do this once a week for a month to make sure that all the pests are eradicated.
Conclusion
Yucca plant leaves turning yellow is indicative of a stressed plant. There is a multitude of reasons for a yucca’s leaves to become discolored. The most common reason is overwatering. Yucca plants are succulents, which means they do not need to be watered very often and are very susceptible to overwatering.
Other causes of yellowing yucca leaves are underwatering, insufficient light, transplant stress and pests.
Yucca plants are very hardy, and as long as you provide them with their basic needs, you will have no problem growing them in your garden.
Image: istockphoto.com / Luca Rossatti