Although there are many members within the extensive Monstera family, they’re all known for one thing: Broad, attention-grabbing leaves. But sometimes your plant can mystify you with leaves that take on a crumpled, curled appearance. What’s going on?
There are 8 common causes of Monstera leaves curling:
- Low Humidity
- Too Much Direct Sunlight
- A Too-Small Pot
- Pest Infestations
- Root Rot
- Natural Unfurling Process
We’re going to take a look at each of these–what’s the cause, what’s the treatment, and how to prevent Monstera curled leaves in the future.
This is the #1 reason for Monstera leaves curling, so if you spot some odd-looking leaves, always check the soil moisture first. Another clue that your plant might be under-watered is if leaves are curled in an upwards and inwards direction.
Leaf-curling is actually a protective mechanism on your Monstera’s part, says Chris Link of Plant Addicts. “A monstera will curl its leaves as a natural response to under-watering. This reduces the surface area of the leaf, which inhibits transpiration (the loss of moisture from the leaves into the atmosphere) conserving their moisture content.”
Besides the unhealthy curled shape, an under-watered Monstera will have very light, dry soil in its pot, and it may also have brown or yellow leaf edges.
How to Rehydrate Your Monstera
Leaf curling is an early sign of dryness, so give your Monstera a good, thorough watering right away.
But if the soil in your pot is so dry that the entire pot is light, you need to do a little more work to rehydrate. You can do this by either bottom watering or watering the soil surface.
Bottom watering. If your Monstera is small enough to pick up, place the pot in a bucket or basin of water for a few hours. Make sure that the pot’s drainage holes are fully submerged and are not obstructed by anything (roots, soil clods, etc).
Leave the pot in the water basin until it has sucked up all the water and the soil is wet from the drainage holes to the soil surface. Depending on the size of your pot, you may need to refill the basin.
If your Monstera plant is too large to easily move around, fill its drainage saucer, let it soak up that water, and refill it again. Do this as many times as necessary until the water makes its way up to the soil surface.
Watering the soil surface. This is much like how you probably water your plant normally- use a watering can or another container to pour water onto the soil surface.
But you’ll need to use a little more care and time when you’re rehydrating a severely dry Monstera. Potting soil often contains ingredients, like peat moss or coco coir, that can become hydrophobic if they dry out completely.
And that’s a problem, according to Claire Akin of Monstera Plant Resource Center. “If soil becomes hydrophobic, the water will immediately drain down the sides of the soil and out the bottom. This leaves the root system dry and not able to soak up any of the water being used.”
If this happens, it can take more than one watering to actually get water to your plant’s roots. Slowly add your water to the soil, giving just a little at a time and allowing it to soak down. Poking a few holes in the soil with a chopstick or skewer can help the water disperse more evenly throughout the soil.
Wait a few minutes, then give another dose of water. The first watering began the work of re-softening the soil, paving the way for the second watering to soak in more deeply. Check the soil again after a couple of hours. If it’s feeling dry, give another watering.
Sometimes, the soil can become so compacted that repeated waterings alone won’t be able to rehydrate your Monstera’s soil. So what should you do? “Repotting the plant into fresh, fast-draining soil is the best course of action,” Claire says.
2. Low Humidity
In their natural habitat, Monsteras live in the understory of tropical rainforests, which is a far more humid environment than your average house or apartment. In fact, according to Khan Academy, average humidity levels are typically between 77% and 88%!
And Monsteras have some special adaptations that allow them to take full advantage of all that easily-accessible air moisture. They are classed as hemi-epiphytic, meaning that they send out specialized aerial roots that allow them to attach to trees (or brick walls, as shown in the photo below) and climb their way up. Besides providing support, aerial roots also absorb moisture and oxygen from the humid air.
And Monstera leaves also help out. They have specialized pore-like openings absorb moisture from the air.
So Monsteras have adapted to thrive in a high-humidity environment. Low humidity levels in the average home, especially when combined with under-watering, often result in leaf curl plus brown, crumbly leaf edges.
How to Raise the Humidity Around Your Monstera
The best (and easiest) way to increase the air moisture around your Monstera is to use a humidifier. These devices allow you to provide reliable humidity for hours every day, and some also let you adjust the mist output or set an automatic timer.
Another effective way to give your plant a moisture boost is misting. While it can definitely help, you need to use some care- spraying your plant with large droplets or leaving excessive moisture pooled on the leaves can cause problems with mold. Also, it’s just plain ineffective for achieving your humidity purposes.
Use a mister that produces an ultra-fine spray rather than a stream of water.
There are a few other strategies for increasing the humidity around your Monstera. These tend to work best if your home is only slightly on the dry side:
- Keep your Monstera in a bathroom or kitchen, where there is more water
- Move away from HVAC vents, which produce very dry air
- Group with other houseplants for a microclimate effect
- Keep a bowl or jar of water nearby
- Place the plant pot on a drainage tray filled with damp pebbles
Also, do not trim the aerial roots on your Monstera- they’re important for helping your plant get the moisture and oxygen it needs. Especially on the Monstera deliciosa, these roots can get pretty long. But just enjoy them as yet another dramatic facet of this plant!
3. Too Much Direct Sunlight
Monsteras are designed to thrive in filtered sunlight, not strong sunshine. If your Monstera is getting too much light, the leaves will typically curl downwards. Also, you’ll also see will actual patches of sunburn, which show up as pale or light brown spots of leaf margins.
The harshest light tends to come from a south-facing window in the Northern hemisphere or a north-facing one in the Southern hemisphere.
How to Give Your Monstera the Lighting It Needs
You can easily moderate the light a Monstera receives from an overly sunny window by simply moving it back a few feet. Another option is to hang a sheer curtain panel to filter the brightness.
And keep the seasons in mind! A window that provides ideal light in the fall, winter and spring may be too harsh during the summer.
4. A Too-Small Pot
Ever worn shoes that are too small? That basically the same feeling a Monstera gets when it has so many roots that they fill up its pot. No wonder it makes the leaves curl!
This is known as being “rootbound.” A surefire sign of your plant outgrowing its pot are roots or rootlets emerging from the drainage holes or even breaching the soil surface.
How to Give Your Monstera More Room
The solution to a too-small pot is to make more room, and there are 2 ways to do that:
Make the root ball smaller. This is the best solution for a large, mature Monstera. Take your plant out of the pot and brush away as much of the old soil as possible. Use a sanitized, sharp scissors or pruners to trim overgrown or compacted roots, taking care not to remove more than 25% of the total root mass. After that, replace your Monstera back in the pot with new soil.
Repot your Monstera into a new, larger pot. This will work for you if your Monstera is still fairly young and small. Even though you’re going for extra pot space here, don’t make the mistake of choosing a pot that’s overly large. Your new pot should be about 2 to 3 inches of room on each side of the root ball.
Follow the same steps of taking your plant out of its current pot and removing old soil. You may need to do some root trimming, but limit it to just taking the ends off of overly aggressive roots. Put some fresh soil into the new pot, set your plant in, and fill in the sides and top with new soil.
Most commercial fertilizers rely on mineral salts to provide the nutrition boost plants need. Those salts can build up, making the soil overly acidic and potentially causing chemical burns.
One way a plant responds to too much fertilizer in its system is by curling its leaves, typically in a downwards direction. Also, fertilizer-induced curling will usually be accompanied by yellow or pale green discoloration.
How to Restore Your Monstera’s Nutrient Balance
To restore your Monstera’s nutrient balance, you’ll need to first flush the excess fertilizer from the soil.
Here’s how to do it:
- Place your pot in the bottom of your shower or outside (in a shady place, and only in warm weather!)
- Drench the soil with water so that fluid drains freely from the bottom holes. If there’s a lot of fertilizer build-up, this fluid may even be greenish or yellow.
- Repeat this flushing action several times over the course of a day. Your goal is for the water to run clear.
- After flushing the soil, put your Monstera back in its usual spot.
- Refrain from watering again until the soil dries out in the top few inches, as the flushing will make things pretty waterlogged.
Going forward, use a lighter hand when it comes to fertilizing. This plant likes a mild monthly fertilization spring and summer months, which is when your plant is actively growing. (Late fall and winter are the seasonal resting phase.)
Use a standard houseplant fertilizer diluted to 1/2 strength. A Monstera-specific formula is another great option.
And always make sure to water your plant well whenever you give fertilizer. Water allows the fertilizer to disperse evenly through the soil, helping prevent damaging salt build-up.
6. Pest Infestations
Yes, pests. The big pests culprits behind Monstera leaf curl are:
- Spider mites
While it often seems that these pests appear out of nowhere, they’re usually either introduced by new houseplants or are attracted by too much water in the soil.
To determine if this is the cause of your Monstera deliciosa leaves curling, check the underside of the affected leaves.
Aphids will show up as small green or black insects:
Mealybugs look like little humps of cottony white stuff:
Thrips can be green or dark brown, depending on the specific species:
Spider mites are tiny insects that produce web-like nests on plant leaves:
How to Rid Your Monstera of Pests
If you have other houseplants, your first step is to isolate your Monstera (preferably in a separate room) to prevent the pests from spreading.
Then physically remove these pests to deal with the problem. If the infestation is very bad, clip off the worst-affected leaves. Tie the cut-off leaves up in a plastic bag or take them outside for disposal immediately.
For less-established pest populations, use a cotton ball dipped in rubbing alcohol or neem oil to remove them. Do this for a few days in a row until you’re sure you’ve gotten all of them, and check on the plant frequently for the next few weeks.
7. Root Rot
Root rot is a fungal overgrowth that causes root tissue death. It most often occurs in soil that’s consistently overwatered.
When root rot sets in, your plant will typically have curled leaves that also turn yellow, plus very wet soil and sometimes black, mushy stems.
How to Treat Root Rot in Your Monstera
Root rot is a serious condition that is often fatal. But if it hasn’t affected the entire root ball, you can sometimes save your plant by performing a little plant surgery:
- Lay the plant on its side, and gently slide the root ball free of the pot. Avoid tugging on any stems.
- Brush away as much old soil as possible, and rinse the root ball out as best as you can. The soil is infected with fungus, so get rid of as much of it as possible.
- Use sanitized scissors or shears to cut off any roots that are brown, black, or mushy.
- If you had your plant in a plastic pot, soak it in a 10:1 water/bleach solution for a few hours, then rinse and air dry. Porous material, like ceramic or terra cotta, can’t be reliably sanitized, so you’ll have to throw them out.
- Add fresh, dry soil to your pot, set your Monstera in and fill in the sides with soil.
- When the root ball is back in its pot, don’t water it for at least a week. This will let the soil dry out and hopefully kill off the rest of the bacteria.
Keep a close eye on your Monstera. Water lightly. It may drop a few leaves, especially if they are already very curled, but in a few weeks it may bounce back.
If you don’t see any signs of improvement, your Monstera is likely too far gone to save. Take any healthy cuttings you can for propagation. Then, unfortunately, you’ll have to throw your plant out.
This video from Crazy Plant Guy does a good job of showing where to take a good cutting and the propagation process:
8. Natural Unfurling Process
Finally, here’s the good news at the end of this long list of bad news!
When your Monstera sprouts a new leaf, it emerges from the stem in a tightly-curled shape. As the leaf grows, it will gradually unfurl and take on the characteristic flat shape Monsteras are famous for.
So you don’t have to spend a second worrying that there’s something wrong with the curled-up new leaf. Just enjoy the show as it becomes a beautiful addition to your plant!
Frequently Asked Questions about Monstera Leaves Curling
The best thing you can do to prevent Monstera deliciosa leaves curling–or leaves curling on any houseplant–is to practice moderation. Not too much water, and not too little; not too much fertilizer; not too much light.
And if leaf curl is a problem for your Monstera, don’t panic! As you saw in this article, there are a number of simple things you can do to help your plant recover.
Have you dealt with leaf curl on your Monstera (or any other plant) before? Did you discover any other tricks that helped speed the recovery up? Let us know in the comments below!