Houseplant spotlight: Thai Constellation Monstera

Learn everything about the Thai Constellation Monstera with our complete guide.

Most gardeners have heard of the Monstera Deliciosa. But the Thai Constellation Monstera, its showy designer variety, might be unfamiliar. Its unusual markings make it a must-have for every discerning plant collector.

There are several types of white and green variegated monsteras out there but the Thai constellation stands out. Its white marks are delicately dispersed across the leaves, resembling galaxy formations. Part of the fun of owning one is seeing what unique pattern will emerge as each new leaf unfurls.

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Before you get starry-eyed about adding the Thai Constellation Monstera to your collection, be aware that cuttings alone go for around 90 dollars. Mature plants can cost hundreds of dollars. Make sure you are somewhat experienced in ordinary monstera care before getting a rarer more expensive variety.

Thai Constellation Monstera care will also be easier if you’ve cultivated shade-loving variegated plants before. Variegated plants require more sunlight than non-variegated varieties because the paler sections cannot photosynthesize. Shade-loving variegated plants are even trickier to care for. While they require higher light levels than their green cousins, they do not tolerate direct sunlight.

Thai Constellation Monsteras are best for:

• Rare houseplant collectors
• Modern indoor spaces
• Fans of monstera
• Partially shaded spaces

What kind of plant is the Thai Constellation Monstera?

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The Thai Constellation Monstera is a lab-grown mutation of the Monstera Deliciosa, a perennial evergreen that hails from tropical Central and South America. In the wild, monstera grow in dense, dark rainforest undergrowth.

The leaves of the Thai Constellation Monstera can be between three to twelve inches wide. Under ideal conditions, it can grow up to 20 feet in height.

While variegated monstera do occur in the wild, they are very rare. First, the chances of a random mutation that creates the white patches are very slim. Second, any white-marked plant is unlikely to survive very long because its green competitors are more vigorous.

Where to grow the Thai Constellation Monstera

In USDA hardiness zones 10 and 12, you can grow the Monstera outdoors. Otherwise, keep your monstera inside for most of the year. During warm and dry summer months, you can leave your potted indoor monstera in a partially shaded spot outdoors to soak up the sun and fresh air.

The ideal indoor space for a monstera is the greenhouse, where can benefit from high air humidity. If growing in the house, make sure you maintain sufficient air humidity (see below for how to do this) and light.

Light

The Thai Constellation Monstera needs more light than the monstera deliciosa. However, direct sunlight will kill it. Lighting your Thai Constellation Monstera is a tricky balancing act between enough brightness and shade.

All monstera are native to the dark, lower reaches of tropical rainforests. They receive sunlight filtered through the dense leafy canopy above it. You need to mimic these conditions as closely as possible for your Thai Constellation Monstera to thrive.

Make sure something is positioned between the plant and the sun so that the plant gets bright but diffuse light. Position in an east or west-facing window facing a large tree or one with net-curtains.

A Thai Constellation Monstera will let you know when it is not receiving enough sunlight. The contrasts between the white and green sections of foliage become less exaggerated - a healthy plant is generally a beautiful plant.

Watering

Water only when the top two inches of the soil is dry – check with your finger. In the spring and summer, this might mean you are watering once a week.

In winter, water very infrequently. Remember that over-watering, particularly in winter, is the most common reason why houseplants die.

When you water, position the soil under a running tap and wait for the water to start running through the drainage holes. Then, place the pot on a dry surface until all excess moisture has dripped out. Place it back into its planter pot once there is no water dripping out of the drainage holes. Never let your plant sit in a pot or saucer with water at the bottom – this may waterlog the soil and cause root rot.

Soil

For optimal health, mix up your own soil for the Thai Constellation Monstera. Combine four parts bark chips, one part perlite, and one part sphagnum peat moss OR coco coir.

Why does this mix work? In the rainforest, monstera grow in soil composed mostly of dead plants that have fallen to the forest floor. The Thai Constellation Monstera therefore appreciates soils high in organic matter, meaning anything plant-based. In our recipe, the bark chips and sphagnum moss or coco coir provide organic content that mimics the nutrient-rich rainforest soils of its native home.

However, organic mixes retain moisture easily. Excess moisture in pots will not drain or evaporate as easily as it does from open soil in the wild. This can lead to waterlogging and root rot. Hence, potted monstera soils need some inorganic materials which allow water to run through the container. In our recipe, the perlite provides the inorganic component. Perlite is a light volcanic rock crushed to coarse grains for horticultural use. Because perlite grains are much larger than the particles of organic matter, they leave open air pockets in the soil. Perlite is also very porous, meaning that it soaks up any excess moisture and releases it gradually.

Note: Most plant guides will advise you to use peat-based compost for monstera and other tropical species. We do not recommend peat in any soil mix. Peat extraction is very damaging to the environment and alternatives like coir, sphagnum moss, or bark chips are often more beneficial for houseplants. Learn why we should be using peat-free alternatives in gardening here. 

Repotting

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Monstera do not like to be root-bound. Pot into bigger containers as it grows. You won't need to do this often as the Thai Constellation Monstera is a slow-grower. Repotting every two years should be enough.

Always repot in spring or summer. The new pot should be less than two inches wider in diameter than the current pot. Fill the new pot halfway with new soil. Remove your plant from its current pot by holding the plant at the stem base and tipping the pot upside down. You may need to tap the bottom of the pot gently for the soil to pop out. Place the plant in the middle of the soil in the new pot and fill in the spaces around it with new soil.

Humidity

Your Thai Constellation Monstera needs very high levels of humidity for optimal health. You can get away with 60 % ambient air humidity but ideally, you want to get it around 80%. If you don’t have ambient air humidity at these levels, you can increase local air humidity around the plant using the following methods:

1. Place the plant on a tray of pebbles with water halfway up the depth of the pebbles. Make sure the bottom of the pot doesn't touch the water. This will make the soil soggy. The idea behind the pebble tray is that the pebbles give a large surface area for water to evaporate off of.

2. Mist the plant with a bottle spray several times a day. If you have a busy schedule and are likely to forget, opt for the pebble tray.

3. Get a humidifier. This is one of the most effective ways of raising air humidity, especially if you have a large number of humid-loving plants indoors.

Fertilizer

This plant is a slow-grower so doesn't need a lot of fertilizer. During the summer months give a regular dose of balanced fertilizer every four to six weeks. Do not fertilize at all during the fall and winter.

Propagation

Make the most of your precious monstera by taking cuttings and growing more plants from them. They make perfect gifts for other gardeners too.

You should propagate during the spring and summer while the plant is actively growing. This will enable the plant to push out a robust root system. In winter, a weak root system might kill the cutting before it has time to mature.

You can propagate Thai Constellation Monstera by taking stem and leaf cuttings. Using sharp sterilized scissors, snip off a stem attached to a leaf just below a stem node. Click here https://southsideplants.com/blogs/plant-care/keiki-paste-for-mega-monsteras-monstera-adansonii to learn how to find stem nodes on a monstera.

Cut the leaves on your cutting in half so that the plant does not lose too much moisture before its root system develops.
Plant the cuttings in a rooting medium. You can make a rooting medium by mixing one-part perlite, one-part coarse horticultural sand, and one-part soil. Or you can simply plant the cutting into moist sphagnum moss.
In four to six weeks, the cutting should be ready to plant in its own small pot. When you move it into its own container, use the soil mix recipe recommended above in the ‘soil’ section.

Styling

Choose a planter in a single neutral color or with simple geometric designs.