You planted ZZ plants for their attractive, wide, dark green leaves. Holes in these leaves is one factor that hinders the plant’s overall beauty. Seeing holes appear in your ZZ plant can be stressful since they may be a sign of a severe problem that can kill the plant.
Your ZZ plants have holes in their leaves because they grow in waterlogged and poorly-aerated soil or have been infested by pests and diseases. While waterlogged soils have insufficient oxygen in the pore space, pests chew on the leaves, leaving chew marks as holes.
In the rest of this article, I’ll take you through the different reasons your ZZ plant has holes in the leaves. I’ll also discuss how to fix the problem. Let’s get started!
7 Causes of Holes in ZZ Plant Leaves
Plants encounter various problems during their growth stage. However, unlike humans, plants can’t speak to tell us what’s wrong. They rely on the change in their appearance or behavior to show us that something is wrong.
Here are some causes of holes in your ZZ plant:
As mentioned earlier, waterlogged soil can lead to holes in your ZZ plant’s leaves. This happens because the excess water in the soil limits the oxygen available for the roots to breathe.
It comes as a surprise to many people that plants need oxygen to stay healthy. Plants indeed absorb and use carbon dioxide for photosynthesis and release oxygen through respiration. However, the roots need oxygen for optimum operations.
Plant roots need sufficient oxygen to burn enough sugar that aids them in absorbing water and nutrients. Lack of oxygen in the roots can cause them to suffocate or die. The suffocation can be manifested through holes in the leaves due to the lack of sufficient nutrients.
The best solution to this is to reduce the watering frequency. You should allow the soil to dry before watering again. A rule of thumb is that the soil’s top two inches (0.05 meters) must be dry to the touch before watering the plant.
Alternatively, you can repot the plant for an immediate solution.
Caterpillars are the larvae of moths and butterflies. These organisms can cause excessive damage to plant leaves and other parts.
Caterpillars wreak havoc on plants by chewing holes in their leaves. Their presence can be identified by small grass (insect excrement) on the chewed parts of the plant.
You’ll always find holes along the edges of the leaves. These holes will be in a line-like pattern since caterpillars make one hole at a point before moving to the next spot.
It’s best to remove caterpillars manually from your plant. However, spotting and removing them can be challenging since they have excellent camouflage. Therefore, you must inspect the ZZ plant’s leaves properly, including the underside.
If you come across many caterpillars, it’s best to use insecticides or soapy water to kill them. Many caterpillars can consume the entire leaf, making it hard for your ZZ plant to grow new leaves.
ZZ plants are not immune to disease-causing pathogens.
Some ZZ plant diseases that can cause holes in the leaves include:
- Bacterial leaf spot: The disease is mainly caused by the bacterium Pseudomonas cichorii. It causes circular spots on the leaves, which may ooze and turn dark. Eventually, the affected parts will die and fall off, leaving holes in their place.
- Fungal leaf spot: The disease is caused by different fungi. It causes small spots on the leaves that may enlarge and coalesce, causing holes to form as the affected parts die.
The best solution is to remove the infected leaves and treat the plant with fungicides or bactericides.
The best prevention for these diseases is by ensuring proper sanitation and avoiding overhead watering.
ZZ plants are tropical and perennial species that thrive in bright, indirect sunlight. Exposing the plant to excessive direct sunlight causes sunburns, leading to holes in the leaves.
The best way to know when your plants are affected by direct sunlight is by looking at the patches on the leaves. Yellow or brown patches on the leaves are signs of sunburn.
The affected leaf parts turn crispy as they dry and eventually fall off, leaving holes in the leaves.
You should never move your ZZ plant outdoors into direct sunlight. The plant is better off in a spot where it receives bright, indirect sunlight. You can place it 3 feet (0.91 meters) away from a south or east-facing window.
If the plant is already affected by sunburn, you can move it to a shady spot and trim off the damaged leaves. Don’t forget to protect it when bringing it outdoors for some fresh air. You can use sheer curtains or sheer fabrics to protect the plant from direct sunlight.
Mites and Aphids
Mites and aphids are the two common pests for indoor plants.
Mites are tiny, spider-like creatures that suck on plant juices, causing discoloration and holes in the leaves. On the other hand, Aphids are small insects that feed on the plant’s juices, causing similar damage as mites.
You can identify mite infestations in three ways:
- Spider-like webbing: Mites spin fine webs on the leaves as they feed on the plant.
- Yellow stippling: Mites also cause yellow stipples or discoloration on the leaves, along with holes.
- Streaks of mite blood: Wipe the underside of your ZZ plant’s leaves with a tissue. If you notice blood on the tissue, then mites are the cause of the holes.
You can easily identify aphids by their presence in large numbers on the plant’s leaves and stems. They also leave behind sticky excrement called honeydew, which often attracts ants.
You can use insecticidal soap or neem oil on the plant’s leaves to control mite and aphid infestations. Make sure to cover both sides of the leaves for adequate control.
You can also remove the affected leaves to prevent further infestation and spread. Inspecting and cleaning your ZZ plant’s leaves regularly is the best prevention for these pests.
Snails and Slugs
Snails and slugs are common pests for outdoor plants, but they can also infest indoor plants like the ZZ. These pests have sandpaper-like mouthparts that feed and wear away tender foliage.
The problem with snails and slugs is that they always hide in the potting mix during the day, only to resurface at night. However, a sure way to confirm that your ZZ plant is infested by snails and slugs is by looking for slimy trails on the foliage.
You can also inspect your plant’s potting mix for the presence of these pests.
Once you see snails or slugs, handpick them from your ZZ plant’s potting mix and place them in soapy water.
You can also create a barrier around the plant’s pot with diatomaceous earth or crushed eggshells to deter them from entering. Ensure to inspect the pot regularly and remove any snails or slugs that get past the barrier.
Pets are among the most excellent human companions, but their curious nature can sometimes cause damage to our plants.
Cats and dogs may chew on ZZ plant leaves, causing holes in the foliage.
Alternatively, as they roam around the plant, they may also accidentally knock off parts of the leaves, leading to holes.
To prevent this, you can place your ZZ plant in an out-of-reach spot for your pets. Furthermore, you should prune and train the plant to grow upwards to make it inaccessible to pets.
You can also spray the leaves with a deterrent made of water mixed with bitter apple or citrus. This will discourage your pets from chewing on the plant’s foliage.
Ultimately, it is essential to properly train and supervise your pets to prevent them from causing damage to your plants.
Pesticides and Insecticides To Control Pests and Insects
Using pesticides and insecticides on an indoor plant like ZZ can be challenging. These chemicals are poisonous and may harm your plant, family, and pets.
Furthermore, excessive use of pesticides and insecticides can lead to resistance in pests, making them harder to control in the future.
If you decide to use these chemicals, make sure to follow the instructions on the label correctly.
It’s also best to exhaust all other natural methods before resorting to pesticides and insecticides on your ZZ plant.
Holes in your ZZ plant’s leaves indicate a problem you must address as soon as possible. These holes can result from pests and insects like mites, aphids, snails, and slugs. Therefore, it’s vital to inspect your plant regularly and take measures to control these pests before they cause further damage to your ZZ plant.
Finally, to prevent waterlogging, you should only water the plant when the potting mix is dry to the touch.