The Swiss Cheese Plant: Monstera deliciosa

The Swiss Cheese Plant: Monstera deliciosa

This week Ali Barwani has Monstera Madness as he investigates this iconic houseplant!

Introduction

Like Hagrid, the Swiss Cheese Plant, or Monstera deliciosa, is a loveable giant! The genus name, Monstera, means ‘monstrous’ telling us about its great size and unusual leaf shape. The deliciosa species name hints at a secret surprise – more of which, later.

Monstera deliciosa is probably the world’s most popular houseplants, and it is certainly the most instantly recognisable with its distinctive glossy green leaves that can reach up to 1 metre in length. Mature Monstera leaves have numerous large holes, known as fenestrations. These windows in the leaves have earned them their popular name – The Swiss Cheese Plant.

Monsteras, like many houseplants, are toxic to pets and children if eaten – so don’t allow kids and animals mingle with your indoor plants!

In Popular Culture

The architectural element of the Swiss Cheese Plant leaf makes it both modern and Instagramable, and yet also vintage and kitsch – something straight out of ‘Mad Men’.

A young Terrance Conran included Monstera in his classic ‘Plant Life’ design for Midwinter Pottery in 1955, where it symbolised modern living just as much as the quartic shape of the plates.

The iconic leaf image of Monstera dominates design today, bringing with it the magic and drama of the rainforest. Swiss Cheese Plant leaves appear on curtains, wallpaper, door mats, dresses, pottery, wrapping paper, placemats, screensavers, candle holders, jewellery, and numerous other decorative products. Large monstera leaves are sold at trendy florist shops, as they look fabulous in a glass vase in contemporary interiors.

In The Wild.

Monstera deliciosa is a hemiepiphyte growing in the understory of tropical forest biomes in Mexico and Central America. In its native habitat it uses its aerial roots to clamber up trees to reach the light of the forest canopy – it can reach as high as 20 metres!

Why Are The Leaves Full of Holes?

A number of theories have been put forward to explain why Swiss Cheese Plant leaves have so many holes, like a slice of Emmental cheese. These include:

1) To prevent the leaves from being damaged during tropical hurricanes. In other words, the wind passes through the holes instead of shredding the leaves.

2) The holes allow the rain to drip through to water the roots far below.

3) To allow light to filter down through the holes in the top leaves to reach the lower ones.

However, a recent study by the American Scientist Christopher Muir of Indiana University has come to a subtly different conclusion using computer simulations. Muir concluded that the holes in the leaves make it more efficient at gathering sun flecks in unpredictable situations. He found that in its natural habitat, the tropic understory, the sunlight filtering down was erratic and unpredictable, and that it was advantageous for the Monstera to have as large a leaf as possible to be able to catch any available rays. He posited that the holes in the leaves allow them to achieve a larger surface area quickly, with lower use of energy and materials to make the leaf – placing them in an advantageous situation for gathering light.

To learn more about this new theory:

https://www.zoology.ubc.ca/files/Muir_2013.pdf

Monstera Care

Swiss Cheese Plants like a bright spot in the house where they will receive indirect light. If they are placed in a very sunny window then I have found that the leaves tend to turn yellow.  Monsteras need space. They have the potential to form large plants, so need plenty of room around them. Large plants respond well to being pruned. The trimmings can often be used for propagation:

https://plantswap.uk/how-to-propagate-monstera-deliciosa-and-create-your-own-jungle/

Monsteras do not like to be overwatered, especially in winter. They should not be left sitting in water. That is to say, excess water should be drained off after watering. I water mine only when the top 4cm of the soil feels dry. Watering frequency can be increased in spring and summer when they are in active growth. I apply a balanced fertilizer every 3 weeks during spring and summer. To increase the humidity of the air around them you can mist them using rainwater or filtered tap water. Their love of humidity makes them good houseplants for the kitchen and bathroom.

Swiss Cheese Plants put out long aerial roots that can seem messy to some people but are part of its attraction to me. These roots support the heavy stem of the plant as it grows, and they also gather moisture and nutrients. Resist the urge to cut these roots, you can always guide them back into the soil or around a supporting moss pole.

To learn more about roots, and the job of aerial roots:

https://www.capitalgardens.co.uk/blog/the-root-zone/

Potting & Repotting

Monsteras like to fill their pots before needing repotting. Repotting is best carried out in spring and early summer when they are beginning to restart growing. Small specimens need repotting once a year if they are growing fast, but it is usually only necessary to re-pot a larger Monstera every two years. A mature plant in its final pot can be kept happy by the application of a balance fertilizer during the year and changing the top layer of compost every other year.

Do not be tempted to overpot your Monstera. If you move it straight into a massive pot it won’t be able to make use of the extra soil, and the moisture in the compost may result in root rot. A couple of centimetres increase in pot diameter is all that is required when repotting.

Swiss Cheese Plants need a free-draining potting compost. A multi-purpose indoor potting mix is ideal for repotting them. I prefer to mix ⅓ potting compost with ⅓ fine orchid bark and ⅓ perlite to create an open mixture. Remember! Always use a pot with good drainage holes, and never plant directly into a cover pot.

A moss pole can be added as a support to help your plant climb. I like to add a moss pole once the plant starts producing long aerial roots. Initially you will need to fix the plant to the pole using soft gardening string or raffia. Don’t tie the string tightly around the plant stem, it needs space to grow. Over time the plant’s aerial roots will begin to grow into the moss pole. The pole supports the plant, enabling it to climb upwards. Monsteras growing up poles will produce larger leaves with more fenestrations than unsupported plants. So, add a moss pole if you prefer Emmental to Gruyère!

The Fruit Salad Plant.

It may surprise you, but Monsteras are flowering plants. They are members of the arum family (Araceae). However, it is rare to see their creamy white spathe and spadix (inflorescence) outside of botanic garden greenhouses in Britain – although it is possible to reach this stage at home, especially with older specimens.

Did You Know? Monstera deliciosa was once grown in English hot houses for their fruit!

As hinted in the introduction – the deliciosa name is a clue to the surprise! The pollinated flower (actually an inflorescence) produces fruit – hence its other name, ‘The Fruit Salad Plant’. This fruit is edible only once it is fully ripe. Before it ripens it is packed with sharp crystals of calcium oxalate! So, it is wise to leave them well alone unless you know exactly what you are doing!

I have eaten the fruit, and it took over a year to ripen on the vine. The scent is delicious, like a mixture of every tropical fruit you could imagine. The taste is delicate and flavourful, with hints of pineapple, strawberry, coconut, and banana – just what you’d expect from ‘The Fruit Salad Plant’!

More Monsteras!

Monstera deliciosa is the most widely grown species of its genus – but it is not the only type of Monstera grown as a houseplant.

According to Oxford University, there are 22 species of Monstera, although only a handful of species are available as indoor plants.

https://herbaria.plants.ox.ac.uk/bol/plants400/Profiles/MN/Monstera

In addition to the regular green Monstera deliciosa you may find various variegated forms, such as ‘Thai Constellation’ and ‘Albo’. These aren’t a different species, but simply have variegated foliage. The price of variegated forms remains very high, although the ‘bubble’ seems to be starting to deflate now. The hype around white splattered forms has been immense.

Monstera adansonii (or Adanson’s Monstera) is a species with smaller, thinner leaves. The fenestrations are plentiful in its leaves. It is often marketed as the ‘Monkey Mask’ plant.

Monstera obliqua has even more delicate leaves than M. adansonii. The leaves seem to be almost entirely composed of holes!

Monstera dubia (or shingle plant) is a beautiful species. They are usually sold growing up a small wooden plank to which the young plants have attached themselves – this flat way of plant growth is known as ‘shingling’.

The juvenile leaf form of this M. dubia is heart-shaped with a fascinating variegation that looks like splashes of effervescent champagne bubbles frozen in time. Its adult leaves are large, dark green, resembling those of the Swiss Cheese Plant.

In Conclusion:

Monsteras are the perfect houseplant. Stylish and sophisticated, yet easy to care for – they make a statement in your room! If you have succeeded growing Monstera deliciosa then, maybe now could be the time to grow your collection with a different form?

Further houseplants reading:

To learn about growing Guzmanias – colourful indoor bromeliads:

https://www.capitalgardens.co.uk/blog/gorgeous-guzmanias-showy-flowering-houseplants/