Zanzibar Gem (Zamioculas zamifolia) otherwise known as ZZ plant is a great plant for indoors or outdoors but if there are holes in the leaves then there could be something wrong.
Zamioculcas zamiifolia can develop holes in their leaves if they are being attacked by pests such as caterpillars, slugs, snails or spidermite. Other causes of holes in ZZ plant leaves include sunburn, damage from pets or overwatering.
This article will explore the top causes of holes in ZZ plant leaves as well as how to prevent and treat them.
Top causes of holes in ZZ plant leaves
The causes of holes in outdoor ZZ plant leaves can be different to those kept indoors. They are more likely to be eaten by chewing bugs such as snails, slugs and caterpillars. Let’s check out the top causes of holes in ZZ plant leaves.
Caterpillars can chew through your ZZ plant at any time of year but they are often around in spring. Look out for chew marks in the edges of your ZZ plant leaf or holes through the middle. Caterpillars will often make a small hole then move on to another area of the leaf creating another hole.
Caterpillars can often be caught on leaves chewing during the day. They have great camouflage though and can look very similar to the ZZ leaf color. Check the undersides of the leaves to see if they are hiding.
To get rid of caterpillars from your ZZ plant I find the easiest way is to shake the caterpillar into a bucket of soapy water. Wear garden gloves and avoid touching the caterpillar directly. You can use a small spade or stick to flick the caterpillar off if it is easier.
2. Slugs and Snails
Slugs and snails can chew through ZZ plant leaves during the night. These creatures will hide in mulch or the organic matter on the ground and then come out when it gets darker and they are protected from birds.
They can crawl up the ZZ plant stems and will chew on the leaves making holes or tearing the edges.
Snails and slugs are harder to catch in the act than caterpillars as they will sneak out after dark. You can get up early to see if they are still out before it gets light.
Preventing slug and snail attack can be as easy as raising your ZZ plant up onto a pot stand. The extra height will make it harder for slugs and snails to reach. You can also add coffee grounds to the top soil around your ZZ plant to deter them. Crushed eggshells also work well as snails and slugs don’t like to crawl over the sharp edges.
3. Sunburn from sudden and direct light
Sunburn is another top cause of holes in ZZ plant leaves. Too much direct sunlight through a window or outdoors can cause burn marks in the leaves. The leaves can develop these brown marks on the edges or holes can appear.
Avoid moving an indoor ZZ plant outdoors into any direct light. Plants that have been kept indoors will not tolerate any direct sunlight and can burn quickly. Move ZZ plants away from windows to make sure they are only getting filtered light.
ZZ plants are one of the most ‘low light’ tolerant indoor plants around so you can use it to darken a space indoors that gets little light. ZZ plants are more likely to be burnt by the sun than they are to suffer in low light conditions.
4. Pets (cats and dogs)
Animals that roam around your home can be the cause of holes and tearing on your ZZ plant. The long stems and hanging leaves can be a tempting toy for a passing cat. Dogs that run freely through the room can also knock and bump into plants causing damage to the leaves.
You can remove any damaged leaves if they look unsightly. The ZZ plant will send up new stems from the rhizome to replace them over time. Pet damage won’t harm the plant overall as long as the underground rhizome is protected.
Move ZZ plants out of the way to make them less appealing to pets and this can save your leaves.
Overwatering is common for ZZ plants because they are so drought tolerant that we tend to love them too much. They grow from an underground rhizome which looks like a small potato. These rhizomes and their thick roots hold water and allow the plant to go weeks without a drink.
Giving ZZ plants too much water can wash away nutrients and cause root rot. You may notice the leaves start to droop or turn yellow.
ZZ plants are usually happy with water around once per month. Thoroughly soaking them once per month and allowing the water to drain through will be enough to keep them happy.
If the soil is particularly wet, soggy or is growing mold on the surface then it is best to repot the plant. They need a small pot with good quality potting soil. Gently water them in when you first plant them but only water again in around 4 weeks.
Fungal growth on ZZ plant leaves can cause yellow or brown spots to form. Watering directly on the leaves can increase the chances of fungus growing on the leaves. Fungal spores can be splashed up from the soil or can travel to your plant in the air or from other plants.
If fungal spots are only appearing on one stem then remove the whole stem and throw it in the bin. If fungal growth is occurring on other stems, spray the plant with a fungicidal spray.
Spidermite are a sap sucking bug that can cause holes in ZZ plant leaves. They are tiny, black or brown and can even have red legs. They can be hard to spot but look out for leaves and tiny, web-like structures on the leaves.
Spidermite can be removed by gently wiping the leaves with a damp cloth. Take the ZZ plant outdoors and spray it with a dilute mix of neem oil and water. This will help to get rid of any remaining bugs that you have missed.
Should I remove ZZ plant leaves with holes in them?
Leaves that have hole and have started to turn brown can be trimmed off. You can remove individual leaves or trim the stem back closer to the soil level. If your ZZ plant only has a few stems you can leave the stems on to allow the plant to continue to photosynthesize.
Holes in ZZ Plant Leaves (Zamioculcas zamiifolia) | Summary
ZZ plants will develop holes in their leaves if they are damaged by pests, insects or disease. Leaves can be removed if they have holes but take care if your plant only has a few stems. Removing too many leaves can slow their growth. Treat any pets quickly and take care when watering. Adding too much water to the soil and leaves can cause problems.