Monstera Leaves Not Splitting? 6 Causes & How to Diagnose

Monstera leaves that refuse to split come down to one of six conditions: the plant is too young, it is not receiving enough light, watering is inconsistent or insufficient, humidity is too low, nutrients are depleted, or you are growing a Monstera variety that does not fenestrate in the same way as Monstera deliciosa.

Five of those six causes are straightforward to fix once you have identified the right one.

Age is the one exception. If your plant is under two years old, no amount of improved care will produce fenestrations, because the plant has not yet reached the developmental stage where splits occur.

For every other cause, the right diagnosis and a targeted correction almost always brings results within a growing season.

This guide works through each cause with the diagnostic detail needed to identify which applies to your plant, and the specific steps to take for each one.

Why Monstera Leaves Develop Splits

In the wild, Monstera deliciosa grows as an understorey plant climbing the trunks of rainforest trees across Central America.

Its leaves can reach 90 centimetres across in mature specimens.

Leaves that large, growing in a canopy where wind and heavy rain are frequent, would be badly damaged if they were solid and unbroken.

The fenestrations serve several purposes. They reduce wind resistance, allowing the leaf to flex and shed air rather than being torn.

Researchers also believe the holes allow dappled light to pass through the upper leaves and reach the lower canopy, increasing the plant’s total photosynthetic output.

A further theory holds that the gaps allow rainwater to trickle down through the leaf to the roots rather than running off the edges.

Understanding this context matters for care. The plant is trying to grow large enough, and receive enough resources, to support the production of complex mature leaves.

Every cause of poor fenestration ultimately comes back to the plant not having enough of what it needs to reach that developmental stage.

How to Diagnose Why Your Monstera Is Not Splitting

The pattern of the problem tells you as much as the symptom itself. Use this table to narrow down the most likely cause before working through the individual sections below.

1. The Plant Is Too Young

The most common reason a Monstera does not produce split leaves is that it has not been alive long enough.

Fenestration in Monstera deliciosa does not begin at the seedling stage. The first leaves a Monstera produces are small, solid, and heart-shaped, with no holes or splits of any kind.

This is not a sign that something is wrong. It is exactly what the plant is supposed to do.

Splits typically begin to appear from around the second year, and only if conditions are good. At this stage, the first small notches or short incisions appear near the midrib of new leaves.

As the plant matures, the splits deepen and extend toward the leaf edge, and true interior holes (the classic swiss cheese perforations) begin to appear in larger, older leaves.

You can read more about what influences this process in our article on getting your Monstera to grow more leaves.

The timeline varies with conditions. A plant in a warm, well-lit home may begin showing small splits slightly earlier than average.

A plant in lower light or cooler temperatures may take longer. There is no reliable shortcut.

If your plant is under two years old and producing new growth regularly, there is nothing wrong with it. All you can do is provide excellent conditions and wait.

You should only start investigating the other causes below if the plant is past three years old and still producing no fenestrations at all.

2. Insufficient Light

Light is the most important variable in fenestration after age. Monstera deliciosa evolved in the dappled light beneath a rainforest canopy, where filtered sunlight intensity is significantly higher than what most indoor rooms provide.

The RHS describes Monstera deliciosa as needing bright indirect light to thrive, and this is especially true if you want fenestrated leaves.

Many people place their Monstera in a position that feels bright to them but that delivers far less usable light to the plant than it actually needs.

A room that feels airy and well-lit to human eyes may receive only a fraction of the photon flux the plant requires for full photosynthesis and, therefore, full leaf development.

A Monstera that is not getting enough light will still grow, but it will produce smaller leaves, and smaller leaves are far less likely to develop splits.

Fenestration is a resource-intensive developmental process. The plant invests more in leaf complexity as it receives more energy to do so.

The signs of insufficient light are often subtle. The leaves do not necessarily yellow or wilt.

Instead, look for leaves that are smaller than expected, a medium or washed-out green rather than a deep glossy green, new growth that is consistently unfenestrated even on a plant past the juvenile stage, and a stem that leans noticeably toward the nearest light source.

See our full guide to Monstera light requirements for more detail on positioning.

What counts as adequate light for a Monstera

Monstera deliciosa does best in bright indirect light, meaning a position within one to two metres of a window that receives good daylight but not direct harsh sun on the leaves for most of the day.

East-facing windows are ideal in the UK, providing bright morning sun that is gentle enough not to scorch the leaves.

South or west-facing windows work well with a sheer curtain to diffuse the strongest afternoon sun. For more placement guidance, see our article on where to place your Monstera.

The plant can tolerate lower light than many tropical species, but it will not fenestrate well in those conditions.

A north-facing windowsill in a UK home is unlikely to provide enough light for reliable fenestration, especially through autumn and winter when day length is short.

Direct harsh summer sun through south or west-facing glass can scorch the leaves and should be diffused or avoided. The goal is high levels of consistent indirect light, not full direct sun.

Using a grow light to supplement natural light

If your home does not have an ideal window position, a grow light is the most reliable solution.

A full-spectrum LED panel positioned 30 to 60 centimetres above the plant for 10 to 12 hours per day delivers significantly more usable light than most indoor positions in the UK, particularly through winter.

This can transform fenestration rates noticeably within a growing season. See our guide to the best grow lights for Monstera for specific recommendations.

3. Inconsistent or Insufficient Watering

Underwatering is one of the more overlooked causes of poor fenestration, partly because Monstera has a reputation for being drought-tolerant.

While it is true that Monstera can survive periods of dryness better than many tropical plants, a plant that is chronically short of water does not grow at its full potential and is slower to produce complex leaves.

When a Monstera does not have enough water, it prioritises basic survival over leaf development.

Photosynthesis slows, cell expansion is restricted, and the plant produces smaller, simpler leaves.

Fenestration requires the leaf lamina to reach a certain size before splits develop, and that size is harder to achieve when the plant is regularly stressed by drought.

The signs of underwatering include wilting between waterings, soil that dries out completely within a few days of watering, and new leaves that emerge noticeably smaller than older ones.

In more severe cases the leaf edges may brown and older leaves may drop. If the plant shows any of these signs, revisit your Monstera watering schedule before investigating other causes.

How to water a Monstera correctly for leaf development

Water thoroughly when the top two to three inches of compost have dried out.

For most Monsteras in standard indoor conditions in the UK, this means watering roughly every one to two weeks in summer and every two to three weeks in winter, but the soil state should always be your guide rather than a fixed interval.

Allow the water to drain fully through the drainage holes after each watering. Do not leave the plant sitting in a saucer of standing water, as this can lead to root rot over time.

The goal is consistent moisture that cycles between moist and slightly dry, not soil that stays permanently wet or regularly reaches bone dry.

Push your finger two to three inches into the compost to test. If it feels dry at that depth, water thoroughly. If it still feels moist, wait another few days and test again.

4. Humidity Too Low

Monstera deliciosa comes from humid rainforest environments where relative humidity regularly exceeds 70 to 80 percent.

Most UK and US homes sit somewhere between 30 and 50 percent humidity, and in winter with central heating running, it can drop lower than that.

The ideal humidity for a Monstera is generally cited as 60 percent or above for optimal leaf development.

The plant can survive at lower humidity, but consistently dry air has a cumulative effect on leaf development.

The cells of a developing leaf need to expand outward from the midrib to reach full size.

If the leaf tissue is losing moisture to dry air faster than it can expand, the final leaf is often smaller and simpler than it would be in better conditions, with less developed fenestrations.

The diagnostic sign that distinguishes low humidity from underwatering is timing. Underwatering causes wilting that resolves within a few hours of watering.

Low humidity causes persistent crispness at the leaf tips and edges that does not improve after watering.

The soil may be moist, the plant may show no wilting, but new leaves repeatedly emerge with slightly browned edges and do not develop as fully as expected.

How to raise humidity for your Monstera

A dedicated room humidifier is the most effective solution. Position it near the plant and aim to maintain relative humidity at 60 percent or above. Inexpensive humidity gauges allow you to monitor the level rather than guessing.

Grouping the Monstera with other plants raises local humidity through transpiration.

A pebble tray filled with water placed beneath the pot allows evaporation to increase the humidity around the plant without waterlogging the roots.

Misting the leaves with a fine spray provides temporary relief and helps remove dust from the leaf surfaces, which improves the efficiency of light absorption.

However, misting does not raise ambient humidity in a meaningful or sustained way. For a full discussion of this, see our article on misting Monstera for humidity.

Bathrooms and kitchens tend to have higher natural humidity than other rooms and can be excellent positions for a Monstera if adequate light is available.

5. Nutrient Deficiency

Fenestration is a complex developmental process that requires the plant to be in good nutritional health.

A Monstera that has not been fed for a long time, or that is growing in depleted or compacted potting compost, will produce smaller and less developed leaves as a direct result.

Nitrogen is essential for leaf and stem growth. Phosphorus supports root development and the plant’s overall energy systems.

Potassium contributes to cell regulation and the movement of water through the plant. When any of these are significantly depleted, the plant slows down and leaf development becomes simpler.

The signs of nutrient deficiency are not always dramatic.

A Monstera that is underfed may simply grow slowly and produce consistently small, unfenestrated leaves despite otherwise adequate conditions.

The foliage may be a slightly washed-out rather than deep, glossy green.

In some cases, more specific symptoms appear: general yellowing of older leaves often points to nitrogen deficiency, while yellowing between the leaf veins with the veins themselves staying green is a sign of iron or magnesium deficiency, typically caused by compost that has become too compacted or alkaline.

How to feed a Monstera for leaf development

Feed every two to four weeks during the spring and summer growing season with a balanced liquid fertiliser.

A balanced NPK ratio, such as 20-20-20, is appropriate for general growth.

During the main growing season you can lean slightly toward a higher nitrogen product to support leaf development, but avoid very high nitrogen feeds that push excessive soft growth.

See our guide to the best fertiliser for Monstera for specific product recommendations.

Reduce feeding to once a month or stop entirely through winter, when the plant’s growth naturally slows and it cannot process additional nutrients effectively.

Over-fertilising in winter leads to salt accumulation in the compost that can damage roots and produce symptoms that look similar to nutrient deficiency.

If the plant has not been repotted for more than two years, the potting compost may be depleted beyond what feeding alone can compensate for.

Repotting into fresh, well-draining compost in spring gives the plant a full nutritional reset and is often the single most effective intervention for a Monstera that has stopped progressing, even when regular feeding has been maintained.

6. Wrong Species or Variety

Not every plant sold under the Monstera name develops the dramatic fenestrations that Monstera deliciosa is known for.

The Monstera genus contains around 50 species, and they vary considerably in how, and whether, they fenestrate.

If you are unsure which species you have, comparing your plant with our guide to Monstera varieties is a useful starting point.

Monstera adansonii produces smaller leaves with interior oval holes rather than the long marginal splits of deliciosa.

The holes appear relatively early in development, but the overall leaf form is quite different.

Monstera Peru (Monstera karstenianum) and Monstera siltepecana produce ridged or silvery leaves that do not develop the characteristic splits or holes of deliciosa under normal indoor conditions.

If you are growing one of these species, the absence of fenestration is not a problem to solve.

It is simply how the plant grows. Our article on whether Monstera Peru fenestrates covers this in more detail.

If the leaves on your plant are bullate (textured and bumpy) or silvery-green rather than flat and glossy deep green, you are likely growing a variety that does not fenestrate in the classic deliciosa sense.

Within Monstera deliciosa itself, some plants take longer to begin splitting than others, depending on how they were propagated and grown before you bought them.

Plants grown from seed start the developmental progression from the beginning and may take longer than plants propagated from mature, already-fenestrating stock.

They will still split eventually, given good conditions.

Does Climbing Help a Monstera Fenestrate?

In the wild, Monstera deliciosa climbs trees as it matures, and its leaves become progressively larger and more fenestrated as it ascends.

Indoor growers have observed that providing a moss pole or climbing support encourages the plant to produce larger and more developed leaves more consistently.

The mechanism is not fully proven, but the most likely explanation is that upright growth encourages the plant toward its natural mature habit, while trailing or unsupported growth keeps it in a more juvenile state.

Many growers who introduce a moss pole to a Monstera that was previously trailing report an improvement in fenestration within a season or two.

The moss pole also maintains higher local humidity around the aerial roots as they attach to the moist surface, which contributes to leaf development.

It is not a guaranteed fix on its own, but it is a useful addition to the other improvements covered in this guide.

Frequently Asked Questions

How long does it take for Monstera leaves to split?

Most Monstera deliciosa plants begin producing their first fenestrations between two and three years of age, assuming they are in good growing conditions.

The first signs are usually small notches or short incisions near the midrib rather than full splits to the edge.

As the plant matures and the leaves get larger, the splits deepen and interior holes begin to appear in the largest leaves.

A plant in very good conditions, with excellent light and consistent humidity, may begin slightly earlier.

A plant in suboptimal conditions may take considerably longer. If your plant is past three years old and still not fenestrating, work through the causes in this guide rather than waiting any longer.

Why do only some of my Monstera leaves have splits?

This is entirely normal. Older, larger leaves on a mature plant tend to be more heavily fenestrated than newer ones.

Newer leaves start smaller and simpler and develop their full form over the weeks following emergence.

Leaves under about 20 to 25 centimetres wide rarely develop splits even on an otherwise healthy and mature plant.

If the plant is producing very small new leaves consistently, that points to insufficient light or nutrients rather than a fenestration problem as such.

See our article on why your Monstera has small leaves for more detail.

Can an existing Monstera leaf develop splits after it has already unfurled?

No. Once a leaf has fully unfurled and hardened off, its structure is fixed. A solid leaf that has already opened will not develop splits later in its life.

Fenestration occurs during the leaf’s development inside the protective sheath, before it unfurls.

This means any improvements you make to light, humidity, watering, or nutrition will only be visible in future leaves, not in existing ones.

This is an important point for managing expectations. If you improve conditions today, the next two or three leaves the plant produces will show you whether the changes are working. Judge progress by new growth, not by what is already on the plant.

At what size do Monstera leaves start to split?

As a general rule, Monstera deliciosa leaves need to be at least 20 to 25 centimetres wide before splits begin to appear.

Below this size, the developmental pathway that produces splits has not yet activated, even in a mature plant.

This size threshold is one reason that improving light and nutrition, both of which lead to larger leaves, is so effective at encouraging fenestration.

A plant that is consistently producing leaves smaller than 20 centimetres is unlikely to fenestrate regardless of how old it is.

Do all Monstera varieties produce split leaves?

No. While most people associate the Monstera name with split leaves, not all species produce the same fenestrations.

Monstera Peru and Monstera siltepecana, for example, do not typically develop significant splits or holes under normal indoor conditions.

Monstera adansonii develops interior holes rather than marginal splits.

If you are growing any of these varieties and expecting deliciosa-style fenestrations, that expectation will not be met regardless of care.

Our article on the most common Monstera pests and our care guide for beginners can help you give whichever variety you have the best possible conditions.

My Monstera is not growing at all. Is that related?

Yes. A Monstera that has stopped growing entirely is unlikely to fenestrate even if it otherwise meets the age requirement.

Stalled growth is usually caused by the same underlying issues: insufficient light, underwatering, cold temperatures, severe nutrient depletion, or root problems.

Our articles on why your Monstera is not growing and how to revive a dying Monstera cover the recovery steps in detail.

Quick Reference: Cause and Fix

Key Takeaways

1. Age comes first. Monstera deliciosa does not begin fenestrating until around year two in good conditions. No amount of improved care can change this timeline. If your plant is under two years old, patience is the only answer.
2. Light is the most powerful lever after age. More bright indirect light, or supplementary grow light, produces more fenestrated leaves more consistently than any other intervention available to indoor growers.
3. Existing leaves will not split. Once a leaf has unfurled, its structure is permanent. Better care shows in future leaves only. Judge progress over the next two to three leaves produced after making changes.
4. Not all Monsteras fenestrate the same way. If you are growing Monstera Peru, siltepecana, or a similar species, absent fenestration is not a problem to fix. It is simply how that variety grows.
5. Consistent watering supports everything else. A plant regularly stressed by drought cannot make effective use of better light or nutrients. Correct, consistent moisture is the baseline.
6. Humidity matters more than many people realise. 60 percent relative humidity or above makes a measurable difference to leaf development quality, particularly in winter when indoor air is drier.
7. Feed through the growing season. A balanced fertiliser every two to four weeks in spring and summer keeps the plant resourced for complex leaf production.
8. Repot every two years. Depleted compost limits leaf development regardless of feeding. Fresh, well-draining compost in spring is one of the most effective resets for a Monstera that has stopped progressing.
9. A moss pole or climbing support encourages larger, more fenestrated leaves over time. It is not a standalone fix, but it works well alongside the improvements above.

Final Thoughts

The vast majority of Monsteras that are not splitting are either too young, not getting enough light, or dealing with one of the straightforward care conditions covered above.

The cause is rarely obscure and the fix is usually practical.

The most common mistake is expecting results on existing leaves or making changes and looking for a response within days. Monstera leaf development is slow.

A leaf takes several weeks to develop inside the sheath before it unfurls. The improvements you make today will show up in leaves produced weeks or months from now.

Get the conditions right, be patient, and the splits will come.

If you found this article helpful, you may also want to read our guides on how to get rid of thrips on Monstera and Monstera adansonii care.