Holes in cannabis leaves are never something to ignore. When healthy foliage starts showing bite marks, ragged edges or small perforations, your plant is telling you that something is wrong. In most cases, holes in cannabis leaves are caused by pests. But stress, disease, and physical damage can also cause them.
At Mediseed Man, we always recommend acting quickly. Leaf damage can get worse fast. This is common during active vegetative growth. Pests have plenty of soft tissue to eat then. The earlier you identify the cause, the easier it is to protect growth, reduce stress and keep your plants moving toward a strong finish.
Not all leaf damage looks the same. Some growers notice tiny pin-sized holes. Others see larger irregular bites along the edges of fan leaves. In more severe cases, sections of leaf tissue disappear altogether.
When inspecting cannabis leaves with holes, look closely for the pattern of damage. That pattern often reveals the cause:
Small random holes often suggest chewing insects.
Jagged leaf edges usually indicate larger pests, such as caterpillars, grasshoppers, or slugs.
Damage that appears overnight is often linked to nocturnal feeders.
Holes paired with slime trails, droppings or eggs make pest pressure even more likely.
Holes with browning, spotting, or rotting around the edges may suggest disease or environmental injury rather than insect damage.
If the problem is not obvious, it helps to step back and assess the whole plant. Check upper leaves, lower leaves, stems, soil surface and nearby vegetation. A full inspection usually tells you whether the problem is isolated or spreading.
For a broader view of how plant problems can change as the plant grows, see The Seven Weed Plant Stages Explained.
You can also read Cannabis Grow Calendar for Australia.
The most common reason for holes in cannabis leaves is pest activity. Outdoor plants are especially exposed, but indoor plants are not immune. Once pests get established, they can damage leaves, weaken growth and make plants more vulnerable to secondary problems.
Caterpillars are one of the most destructive causes of holes in marijuana leaves. They chew through soft leaf tissue quickly and often leave irregular openings across large fan leaves. Some species also move into flowers later in the cycle, where they can cause even more serious damage.
Signs of caterpillar damage include:
Larger uneven holes
Fresh chew marks on leaf edges
Black droppings on leaves or nearby surfaces
Damage that seems worse in the morning after overnight feeding
The fastest treatment is manual removal. Inspect plants at dusk or after dark with gloves and remove any caterpillars you find. On non-flowering plants, some growers use organic pest controls, but choose products carefully and use them for the current growth stage.
Crickets can also cause small to medium holes in leaves, particularly when they feed at night. Because they move quickly and hide well, growers often notice the damage before they ever see the insects themselves. Some species also disturb the soil, which can add root-zone stress to visible leaf damage.
Good garden hygiene helps reduce cricket activity. Clear dead plant matter, remove hiding spots and inspect around pots, beds and borders.
Grasshoppers create more obvious chewing damage. They can strip sections from leaves and reduce overall foliage quickly if several are feeding on the same plant. Outdoor plants face the highest risk, especially in dry areas with little nearby vegetation. In these areas, cannabis can become an easy food source.
If you are growing outdoors, physical inspection and deterrence matter. Reducing nearby overgrowth and encouraging natural predators can help limit repeat visits.
Slugs and snails are classic culprits when you find irregular holes in cannabis leaves. They tend to feed at night and often target young, tender growth first. Their damage usually looks messy rather than clean, and they leave behind the clearest clue of all: a shiny slime trail.
If you suspect slugs or snails:
Check plants at dusk or early morning.
Look under pots, under leaves and around damp shaded areas.
Remove them by hand.
Reduce excess moisture and unnecessary ground clutter near plants.
Outdoor growers can also improve prevention by strengthening the growing environment. How to Protect Your Outdoor Grow is a strong companion resource here, along with The Best Companion Plants for Your Cannabis.
Yes, but the damage may look different at first. Very small pests do not always leave dramatic chew marks. Instead, they may cause fine stippling, weakened tissue or damage that worsens until leaves tear or collapse.
Thrips, for example, can scar leaf surfaces and create damage. Over time, it may look like tiny holes or thin patches. If you suspect this type of issue, read How to Naturally Get Rid of Thrips.
Broad mites are another concern because they distort new growth and weaken leaf tissue, even if the damage does not begin as obvious holes. See How to Deal With Broad Mites on Cannabis for a closer look at that problem.
If you cannot find insects, do not assume the problem is harmless. Holes can also develop from environmental stress, disease or physical damage.
Excess heat or overly intense light can weaken delicate leaf tissue, especially on upper growth. In severe cases, damaged areas dry out and tear, leaving holes or brittle sections. This is more likely indoors, where lighting is strong and airflow is poor.
If your plant shows stress near the canopy, review Cannabis Plant Heat Stress Prevention. Also review Cannabis Wind Burn: How to Identify & Treat It. Wind damage can rough up leaf surfaces and make tears more likely, especially when plants are already stressed.
Some fungal or bacterial issues can kill small patches of leaf tissue, which later dry, crack or fall away. When this happens, the result can resemble holes. In these cases, the surrounding tissue often appears discoloured rather than fresh.
If the damage comes with spotting, browning or yellow halos, these guides may be relevant:
Leaves can also tear from handling, strong winds, or hail. They may tear from rubbing against cages or branches. They can also tear from general stress during training and maintenance. Physical tears are usually easier to spot because they follow a split or rip pattern. They do not follow a feeding pattern.
If your plants have recently been trained or moved, consider whether the damage happened mechanically. Cannabis Pruning: Why, When and How can help growers avoid unnecessary stress during maintenance.
Treating holes in cannabis leaves starts with identifying the cause. Spraying first and asking questions later often makes the problem worse. A simple, methodical response works best.
Check both sides of the leaves, stems, leaf joints, the soil surface and nearby structures. Many pests hide during the day, so inspect at dusk if possible.
If caterpillars, slugs or snails are present, hand removal is often the fastest first step. This immediately reduces active feeding pressure.
Do not strip the plant bare. Leaves still support growth even when imperfect. Remove leaves only if they are heavily damaged, decaying or creating conditions for disease.
Better airflow, cleaner surroundings, and reduced moisture buildup make many pest and disease issues less severe. Outdoor growers should clear debris. Indoor growers should review fan strength, humidity and sanitation.
Organic or low-impact pest controls may help, but treatment should match the pest and the plant’s growth stage. Be especially cautious in the flower. Anything applied to buds can affect the quality, aroma and overall cleanliness of the final product.
Once you find holes in cannabis leaves, keep checking every day until the pattern stops. New damage indicates the root cause remains active.
Prevention is always easier than recovery. Strong, healthy plants are more resilient, and clean growing conditions reduce the chance of serious infestation.
At Mediseed Man, we recommend these prevention basics:
Inspect plants regularly, not just when damage appears.
Keep the area around plants clean and free of decaying matter.
Avoid overcrowding and maintain good airflow.
Protect outdoor plants from unnecessary exposure where possible.
Support overall plant health with balanced watering and nutrition.
Use companion planting and garden biodiversity to discourage problem pests.
A few helpful support articles are available.
These include Growing Cannabis Outdoors in Australia.
They also include Growing Cannabis Indoors Australia.
Another useful read is Over and Underwatered Weed Plants.
Holes in cannabis leaves usually mean something is actively damaging your plant, and in most cases, that means pests. Caterpillars, crickets, grasshoppers, slugs and snails are all common offenders, especially outdoors. But if no insects are present, environmental stress, disease and physical damage should all be considered.
The key is to respond early. Inspect carefully, identify the pattern, remove the cause and stabilise the growing environment. A few holes may not ruin a crop, but ignoring the issue can slow growth. It can also raise plant stress and cause worse problems later.
Healthy plants begin with strong genetics, a stable setup and consistent observation. When you stay ahead of plant stress, you give your plants the best chance to perform from start to finish.
The most common cause is pest activity. Caterpillars, slugs, snails, crickets and grasshoppers can all chew through leaf tissue. In some cases, heat stress, disease or physical tearing may also be responsible.
No. Pests are the most common cause. But holes in weed leaves can also come from light stress. They can also come from wind damage. Other causes include disease, frost injury, or damage during handling and training.
Look for irregular chewing patterns, slime trails, droppings, eggs, leaf-edge damage, or signs that the problem worsens overnight. Inspect both sides of leaves and check the plant after dusk for the best chance of spotting active pests.
Yes. Cannabis can recover well from minor leaf damage if the cause is found and corrected early. The damaged leaves will not repair themselves, but healthy new growth can continue once the issue is resolved.
Only if they are badly damaged, diseased or interfering with airflow. Slightly damaged leaves can still contribute to photosynthesis, so avoid unnecessarily removing too much healthy foliage.
Regular inspections, clean growing conditions, good airflow, balanced watering, and quick pest control help prevent holes in cannabis leaves. Outdoor growers should also reduce hiding spots for pests and consider protective garden strategies.
To properly Read More
To properly Read More
To properly Read More
2026 2 March
Picture a modern Australian evening: a cork twists from a wine bottle, a jar clicks…
2026 28 February
This paper contributes to the sensory analysis of wine and cannabis by examining their shared…
2026 27 February
If you're asking, "Which cannabis seeds can I legally buy in Australia, and why does…
