A staple of many homes, the Yucca is definitely one of the most popular houseplants out there. Although they can very easily adapt to a variety of different environments, if things aren’t right you may still discover some issues slowly developing. One of these problems is that the leaves start curling. This can happen both inwardly and outwardly as a sign that your plant is struggling.
Luckily though curling leaves are often one of the earlier signs of unhappiness so if there are no other visible symptoms then it should mean you’ve caught the issue early. Below we will go through each of the different causes of curling leaves on a Yucca so that you can successfully diagnose and treat the issue effectively.
Overwatering is a common cause of curling Yucca leaves
Whilst overwatering can have some severe effects on Yuccas and other houseplants, curling leaves are often an early warning sign that the soil has become waterlogged and that the root system has started to rot. This can appear alongside leaf loss and yellow leaves as the issue progresses and the root system becomes more and more damaged.
Yuccas like their soil to dry out and don’t deal so well with waterlogged potting mix. They can easily go for weeks without water which is one of the main reasons they are such a loved low-maintenance plant. So if there is one extreme it prefers it is often underwatering (but more on that later).
It’s important that you diagnose the issue of overwatering as quickly as possible as this is one of the fastest issues to kill your plants if not solved.
To confirm the issue, remove your plant from its pot and check for rot and waterlogged soil. If your Yucca has become quite large and you are unable to lift it and repotting is difficult then there are other ways to check soil moisture. Using the chopstick method or a moisture meter can help figure out how soggy the soil is. Unfortunately, the only way to know if the roots have started to rot is by removing the plant from its pot.
If the roots have started to rot they will be mushy and dark in colour. Healthy roots however are pale and firm to touch. If you find the root system has started to rot, trim away the infected parts and add fresh (dry) soil.
Moving forward, now that you’ve done all you can to stop overwatering from causing more harm, for now, it’s important to flip your attention to long-term prevention. If you continue watering your Yucca at the same rate as before, it won’t be long until the issue returns.
It’s vital that you adjust your watering schedule so that you are either watering less frequently or deeply. Either will help give your Yucca enough time to dry out. You also want to be making sure that you check the soil has dried out before rewatering.
Underwatering can also be harmful to your Yucca
Although Yucca plants are known for needing little water and thriving in dry soil, if underwatered for too long it can cause issues such as curling and brown leaves. You will be pleased to know however that underwatering isn’t a quick killer of Yucca plants so you should be able to revive it fairly easily.
Before underwatering causes dry crispy brown leaves, it will usually start off by showing itself as curling leaves. This is a mechanism that Yucca plants (and many other plant types) use to reduce the loss of moisture.
There are a few different factors that can cause your Yucca to start curling as a result of underwatering so it’s important to find the one that fits your plant care so you know how to fix it.
Watering the Yucca too lightly (Yucca plants require an infrequent but generous soak).
Not watering frequently enough (although Yucca plants are somewhat drought tolerant, they still require scheduled watering, especially during heatwaves and hot months).
Lower humidity can also increase transpiration from the leaves causing them to dry out and start curling as they simply require more water than normal.
Your plant is in water-repellent soil. (If the soil being used is peat-based it can dry off quickly to form a hard potting mix. This then repels water from the surface and it runs down the pot without actually reaching the roots.)
The best way to diagnose and confirm that underwatering is causing your Yucca to start curling is to remove it from its pot and inspect the soil and root system. If you notice that the roots have turned dry and crispy then this indicates underwatering.
How to fix the issue of curling leaves caused by underwatering
Give your Yucca plant a 10-15 minute soak. This will ensure the root system takes up the water rather than it all just running out of the bottom of the pot.
Adjust your watering schedule moving forward so that you are watering more generously or more frequently (whichever you weren’t doing before).
Monitor the environment to pick up on any fluctuations that might mean your plant is drying out quicker (low humidity, higher temperatures and more sunlight). This will help you spot when you need to increase watering before it’s even caused an issue with your plant!
Low light levels can harm your Yucca’s health
Although these plants can deal with a range of environments and light levels, if your Yucca isn’t getting enough light it can start to cause some problems over time, one of the most common being curling leaves.
If you don’t have a light monitor then it can be tricky to scientifically measure the amount of light your Yucca is getting but check in with it several times a day to see the sort of light it is getting. If your plant is growing in the darkest corner of the room then this could definitely be the cause.
You will tend to find curling leaves as a result of low light more common in winter for obvious reasons. It can then be difficult to find a sunnier spot for your plant so you might want to invest in an LED grow light to supplement light levels. They are a great investment to pull your plants through the winter!
Too much sunlight can also cause curling leaves
Direct sunlight will very quickly scorch and burn the leaves of your Yucca which is, unfortunately, irreversible. It will dry out and burn the leaves so look out for any scorched patches on the curling leaves that are most exposed to the sunlight (facing the window).
If you think that direct sunlight is the cause of the curling leaves on your Yucca, move your plant to a slightly shadier spot in your home. This might be a little bit of trial and error as you figure out where the right balance is as you don’t want to move it somewhere super dark.
We recommend only removing the leaves if they are badly scorched as if the only problem is curling, this can sometimes fix itself once your plant is in a better environment. If there are any leaves, however, that are nearly fully yellow then it’s best to remove these to prevent your plant from wasting valuable energy trying to keep these alive.
Curling Yucca leaves can mean cold temperatures
If watering isn’t the issue, then it can be quite common that extreme temperatures can cause curling leaves on a Yucca, in particular cold air. As they are native to hot and dry parts of the Americas, Yuccas thrive in warm temperatures.
If they are placed next to a drafty window or door or are in a cool room in your home then they will struggle and the leaves will begin to curl. But it’s not just winter weather that you need to be concerned about as air conditioning units can be a real nightmare for warmth-loving houseplants. You need to be sure that your plant isn’t sitting in the direct line of the unit.
Look out for pests
Whilst pests are a rarer issue compared to some of the problems listed above, they can be a very (very) worrying problem so it’s important you rule it out straight away.
The first thing to do is inspect your Yucca fully by looking at the undersides of the leaves, the stems and also in the potting mix. You want to look out for any of the following signs: holes in the leaves, brown or yellow spots, white webbing, white powder and of course visible pests on the plant or in the potting mix.
If you do find pests (or even a single sign of them) isolate your Yucca immediately to stop the spread across your other plants and make sure to inspect your entire urban jungle. Pests can easily jump across leaves that are close to each other so you want to isolate your plant immediately.
We recommend giving your infected Yucca a shower. As they have quite sturdy leaves you can get away with putting the water pressure a little higher than you would for a lot of other more delicate plant types.
Then treat with neem oil and an insecticide to fight the infestation. If you spot any areas of your plant that are a lot more infected than others, remove those leaves as this will cut down the number, making the pests easier to win against.
Those are the most common factors that can lead to curling leaves on a Yucca. Once you have made some changes to its care or environment, it’s crucial that you keep a close eye on your plant over the next few weeks. This will help you make sure that everything is progressing in the right direction and help you spot any other issues that are arising out of those changes early.
To learn more about how to keep your plant thriving, check out our Yucca care guide.