ZZ Plants are becoming more and more popular due to their fairly easy care requirements. However, if you find that your ZZ’s leaves are starting to turn brown, it tends to be your plant telling you that something isn’t quite right. But if you have caught the problem early and fix whatever it is that is causing the brown leaves, then your ZZ Plant should return to full health pretty quickly. The most common causes of brown leaves in ZZ Plants are: overwatering, underwatering, chemical sensitivity and a lack of humidity.
Overwatering can quickly lead to brown leaves
If the leaves on your ZZ Plant have turned brown and a little mushy you are most probably overwatering. Another sign of this is if some of the brown leaves are starting to fall off.
Overwatering is one of the main killers of ZZ Plants as you might not always be able to tell before it is too late. ZZ Plants don’t like to be sitting in a lot of water for long periods of time as this can lead to root rot meaning the plant becomes unstable and also cannot get needed nutrients from its root system. Waterlogged soil also gives off quite a damp and musty smell so get up close to your plants every so often to check on this.
If you think that the brown leaves on your ZZ Plant are a consequence of overwatering, check the moisture of the soil immediately and adjust watering accordingly. The most reliable way to do this is by using a moisture meter which will tell you how damp or dry the soil is.
We also recommend replacing the potting soil straight away (rather than waiting for it to naturally dry out) so that the roots can begin to recover. Cut away the rotten roots and brown leaves so that the plant focuses on regenerating healthy growth. You’ll want to use a high-quality potting mix such as this one from Miracle Gro to make sure your ZZ Plant gets the right balance of nutrients.
Underwatering can also cause brown leaves
If your ZZ Plant’s leaves have become quite brown, dry and crispy (starting from the tips) it may be because you have underwatered your plant for a while. Although your ZZ Plant won’t die on you suddenly if you forget to water it every once in a while, or make it go a little longer without water whilst you are on holiday, consistent underwatering will start to have an impact on your plant’s health and brown leaves might only just be the beginning. It is important to keep an eye on the moisture levels of the soil so you know when your plant is ready for watering.
Make sure to check the moisture in the soil before you water your ZZ Plant. There are a few really easy ways to make sure that it definitely needs water. First check the moisture at the top of the soil, if it is still damp then wait a few days before watering again. You can also lift up your ZZ Plant to check the weight of the plant before and after watering. You will then start to be able to gauge how heavy the soil is when it is in need of water. Using a moisture meter is another way to be sure about how dry the soil is.
If you find that your ZZ Plant feels very dry, water it a little every other day for a week. Your first instinct might be to give it loads of water straight away but this can actually be harmful to your plant if the soil goes from one extreme to the other. Yes, plant’s can get shocked too by a sudden change in environment. So instead you want to reintroduce frequent watering for a week or two and this should solve the problem.
Luckily underwatering won’t instantly kill your ZZ Plant so you have time to rectify the problem before it is too late. Trim away the brown leaves and any new growth should hopefully be healthy and luscious green!
Brown spots may be caused by chemical sensitivity
ZZ Plants can actually be a little sensitive to fluoride that you find in tap water. Over time, this may be causing harm to the roots which often shows itself in brown/yellow leaves on your ZZ Plant. If you live in a hard water area, it may be that your ZZ Plant is reacting to high levels of chemicals in the water.
There are a few ways to make sure that the water you give them is free of both these chemicals. Firstly you can leave a jug of tap water for around 24 hours to allow for a lot of the chemicals to evaporate. Another method is leaving a tray outside to collect rainwater to give to your houseplants to make sure chemical levels are lower than the treated water that comes out of your tap. Some plant parents also have a filter system for their houseplant water but we find that the methods above work just as well!
Lack of humidity can also cause brown ZZ Plant leaves
Alongside watering, it is important that you try and increase the humidity for your ZZ Plant get it back to tip-top condition. Often our homes can have quite dry air, especially in the winter months where we often have the heating on for several hours in the day. A lack of humidity in the air can cause your ZZ Plant’s leaves to be a little limp, droop down, and turn dry, brown and crispy from the tips up.
But luckily for plant parents, it can be pretty simple to increase the humidity for your ZZ Plant, here are our top tips:
Misting the leaves
One of the simplest ways to increase the humidity for your ZZ Plant is to mist them with a spray bottle a couple of times a week. We love these amber glass spray bottles from Amazon.
Place your ZZ Plant over a tray of pebbles with fresh water over the top. Over the day water from the tray will evaporate giving your plant exactly what they’re looking for.
Give your ZZ Plant a shower
To quickly raise the humidity and wash down your plant of any long-standing dust, you can always give them a quick shower. Simply pop them in the shower and wash them down with lukewarm water, this will clean off the leaves and give the soil a good soaking. You will want to keep the water pressure fairly low so you don’t cause any further damage to the leaves or stems.
Move your ZZ Plant to the bathroom
If you’re lucky enough to have great lighting in your bathroom you can move your ZZ Plant in there to increase the humidity. The running water from your showers means your bathroom is probably one of the most humid in your home and a great place for your houseplants to thrive in.
Buy a humidifier
They’re relatively affordable little devices and they make keeping a consistent humidity level so much easier. Most will allow you to place them on a timer so they run on a fixed schedule, and some will even have a built-in monitor so they automatically turn on and off to keep the humidity exactly where you want it. We recommend this humidifier from Amazon – our plants love it!
Want to know more about how to raise the humidity for your ZZ Plant and other houseplants? We have written a whole guide on this.
The odd brown leaf on your ZZ Plant isn’t the end of the world but if you find that quite a few leaves are turning brown, or maybe entire areas of the plant are then its definitely a cause for concern. It is important that you are able to diagnose why your ZZ is developing brown leaves early and put a few steps in place to encourage healthier growth. By shifting your watering schedule and keeping a close eye on your ZZ to spot any further signs of unhappiness, it should return to full health quickly. Don’t expect the brown leaves to all of a sudden turn luscious green with a bit of TLC, what’s done is done. Another tip from us is to make sure you don’t pull away the brown leaves as this can harm your plant. Instead, wait for them to drop naturally or carefully prune away the brown leaves with sharp scissors or shears once your ZZ Plant has resumed healthy growth.
Check out our detailed ZZ Plant Care Guide for more information on general care tips and diagnosing other common problems.
Written by Joanna Turner