Yucca plants are appreciated for their unique shapes and striking textures, providing lush greenery and interest in the water-wise garden.
These low-maintenance perennials are highly versatile in the landscape, with different varieties sporting diverse growth habits.
Usually problem-free, a common sign of faltering plant health is yellow or otherwise discolored foliage. And to effectively remediate the problem we need to figure out what’s causing it first.
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In our guide to growing yuccas, we cover care requirements of the most popular species grown in home gardens.
There are varieties of yucca that have variegated foliage which includes yellow, but what we’re addressing in this guide is green foliage yellowing as a result of stress.
From root rot to low light conditions, there are five common reasons why the foliage may turn yellow, and the quicker you find out the cause, the sooner you can get to work fixing it.
Read on to learn about five common causes of yellow leaves in yucca plants:
1. Inappropriate Light
Yuccas like bright, hot environmental conditions. Sun-starved specimen may gradually turn yellow, and will generally look a little limp and wan.
If you’ve planted your yucca in a spot in the garden with less than six hours of bright sunlight per day, try moving it to a brighter location and observe its response.
Most of these plants need at least eight hours of direct sunlight per day.
The popular spineless variety (Y. elephantipes) is one exception, this species typically prefers bright, indirect sunlight.
On the flip side, although these plants love the sun, if they’ve been kept indoors through the winter, they have to be reintroduced outside very gradually or the foliage can suffer from sunburn.
Tossing your potted specimens outside into bright sunshine as soon as the weather is warm can result in pale, blanched, and sometimes yellow leaves.
Most yuccas are able to recover from a little sunburn, but taking your plants out for a couple of hours at a time over the course of a few days will help them make the adjustment smoothly.
2. Moisture Issues
Let’s start with the most common cause of yellowing leaves. Although we all want our plants to prosper and grow, when it comes to watering, more is not always better.
This is especially true for species in the Yucca genus, many of which are adapted to low rainfall environments, like the Mojave desert.
In regions with high humidity, yuccas rarely need to be provided with supplemental water.
In locations with regular rainfall, you need to ensure that the soil is well-draining or they can become oversaturated. Indoors, hydration two to three times a month should be sufficient.
Make sure your plants are sited in freely draining soils. If your garden has loamy substrate, throw in several shovels of grit before planting. Potted specimens should always be planted in a medium that drains quickly, such as a succulent mix.
Yellowing leaves that appear as a result of overwatering are a sign of stress, and if the problem is not addressed, can quickly lead to root rot, discussed below.
Although underwatering is not a common cause of yellowing leaves in these drought-tolerant perennials, we are all guilty of a little neglect at times.
If your plant has yellow foliage and it’s been more than a couple of weeks since it was watered, go ahead and check the soil.
If it feels bone dry, and the temperatures have been hot for any length of time, go ahead and give the plant a good drink.
Underwatering can be a problem in container-grown yuccas, as particularly during hot weather, pots tend to dry out more quickly than garden soil.
3. Nutrient Deficiency
If grown outdoors in the landscape, yuccas generally do not need fertilization.
Inside, potted plants may benefit from occasional feeding, especially if they’re planted in the nutrient poor, freely draining soils these plants prefer.
Make sure your plant is not overwatered, underwatered, and is receiving adequate sunlight before assuming the yellow leaves are a result of a lack of fertilizer.
Nutrient deficiencies are very uncommon and an overabundance of plant food can itself cause yellowing leaves, too.
To feed your yucca, choose a mild, balanced fertilizer. The best time to fertilize these plants is in early spring, however, if you notice yellowing leaves and can’t find the cause, you can try a single dose of fertilizer at any time of year.
4. Pest Infestation
There are very few pests that do significant damage to yucca plants.
If you’re growing your plants in pots indoors you may run into the usual cast of pesky characters including aphids and spider mites.
These two common pests love crowded, humid environments and stressed plants.
Even if your house may not feel particularly humid, the lower light levels of most homes can stress the plants, leaving them susceptible to infestation.
The damage both aphids and spider mites inflict can cause drooping, yellow leaves.
Once identified, infestations can typically be controlled by dutifully removing the insects with a wet cloth and spray bottle filled with water.
If the infestation is severe, insecticidal soap or neem oil works well to kill both spider mites and aphids. Make sure to read the directions on the bottle carefully prior to application.
5. Root Rot
Root rot is a catch-all term for – you guessed it! – rotten roots. This condition is generally seen in warm, oversaturated soil.
It may be attributed to infection via a number of different pathogens, including fungi and oomycetes, or it can simply be a result of the roots drowning in too much water.
Root rot reduces the yucca’s root system to a sloppy, slimy, often stinky mess, completely eliminating the ability to transport water and nutrients.
Unfortunately, once this devastating disease begins, it can only be curtailed if caught in the very early stages.
To prevent root rot, grow your yuccas in freely draining soils and water rarely, only when the soil has dried out completely.
If you see foliage beginning to turn yellow, pull back on your watering and assess your plant’s environmental conditions. It may be that several variables are at work at the same time.
If you suspect root rot to be the cause of the yellowing leaves, you’ll need to dig up the specimen, trim off any diseased roots and treat with a fungicide, before replanting in fresh potting medium.
You can learn more about root rot in our guide.
A Cry For Help!
Think of the yellowing leaves as an early distress signal. Although discolored foliage is a cry for help, it’s likely not too late to remedy the problem.
Take action and run down this checklist and remember, fixing the source of the issue may take time.
Do you currently have a yucca with yellowing leaves? What’s the source of the problem? How did you fix it? Let us know in the comments section below!
And to learn more about growing and caring for yuccas in your landscape, check out these guides next:
