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Unlike the peace lily (low light) or the alocasia (medium light), the Monstera needs bright light.
Different plants need varying degrees of available light to produce the food they require. The Monstera has adapted to optimize light when young by keeping its leaves free of fenestration. As the plant matures and, having climbed a host tree to brighter light, fenestration increases.
Monstera Changing Light Usage
Epiphytes, like some Monsteras, have a form of negative phototropism called skototropism. Instead of growing towards the light, skototropic plants grow towards the darkest shape on the horizon, hoping to find a tree to climb.
Heteroblastic Leaf Morphology
Heteroblasty is the significant change in the form and function of plant parts (like Monstera leaves) as they grow.
Young Monstera plant leaves have a completely different appearance from adult plants.
Young Monstera plants grow towards the darkest space on the horizon as evolution has taught them that the dark shape represents a tree.
They know they can climb the tree to reach greater heights (and better light).
The leaves develop closely, overlapping one another up the tree trunk. The Monstera leaves only split and fenestrate when they become older and are exposed to more light.
Brighter Light for Young Plants, Medium Light for mature Plants
You can boost leaf-splitting and fenestration by exposing younger plants to brighter light but guarding against sun damage.
Monstera Light Needs
Most aroids need plenty of dappled light, especially for maintaining variegation. Plants like the Monstera standleyana are medium-light plants that need 15 watts per square foot.
In the Northern Hemisphere, medium bright light (100 – 500 FC) indoors will be provided by the sun entering an east or west-facing window.
The sun entering south-facing or west-facing windows will provide high indoor light (500 – 1000 FC).
Most plants require a period of darkness to develop correctly, and the absence of light triggers some plants to flower and bear fruit.
Monstera should have at least 8 hours of the night’s darkness, including a lack of artificial light.
How Light is Commonly Quantified
Light is generally quantified in foot-candle or lux, but growers may use low, medium, and high terms. Other growing guides may use words such as full sun, partial shade, partial sun, or shade.
Below is a table clarifying what is meant by each term.
|Foot-candles||Light Level||Description of area’s light intensity at mid-day|
|25-100 ft.c||Low||Typically, areas with this low light intensity receive relatively little natural light, and many merely have overhead lighting. They frequently inhabit areas that are far from windows or that are substantially shadowed.|
|100-500 ft.c||Medium||Although no direct sunlight is present, areas with more moderate light intensity are typically near windows. They can frequently be found in east or west-facing windows that are shaded or in north-facing windows that are not.|
|500-1000 ft.c||High||Higher light levels are typically seen near windows, where they may also receive some direct light. However, if there is direct light, it is muted by outdoor greenery or shaded by window coverings. They frequently hang out under windows with an unobstructed east or west orientation. It may also be seen close to south-facing windows that are shaded.|
|Over 1000 ft.c||Direct sunlight||These spots are right in front of windows, with nothing but transparent glass standing between the plants and the sun. For plants that require “direct light,” four or more hours of sun exposure is ideal. This is typically observed in windows facing south or southwest that are not shaded.|
Listening to Your Monstera
Plants are great because they can “tell” us when something is wrong or they aren’t receiving what they need. Plants that stretch/elongate or appear spindly indicate inadequate light.
Defoliation or poor color are other indicators but can also indicate watering issues. Remember that light intensity will be reduced in winter, and you may need to provide supplemental lighting.
Rotate your indoor plants regularly so that all sides of the plant will benefit from the light coming in the window. This, however, is not needed with skototropic plants as the reverse applies.
The Best Position for Monstera
The first rule for all plants is to put the appropriate plant in the right spot.
Knowing how much light is available in your home will help you choose plants that thrive there. Instead of putting a plant into lighting conditions where it won’t survive, find one that fits your available lighting.
For instance, if you have a room with a north-facing window that doesn’t get much sunshine, consider species like Pothos or Philodendron to put in it, rather than bright light-loving ones like Monstera.
It is good to “zone” your home before purchasing plants. Assuming there are no external light obstructors, the following is how windows are classed for light availability:
- Low Light – North-facing windows
- Medium Light – East or West-facing windows
- Bright Light – South-facing window (ideal for Monstera)
As we’ve seen, Monstera plants are ingenious, managing their leaf morphology to respond to prioritized needs. As light levels increase, so do fenestration and leaf splitting.