Aerial roots are roots that are, in whole or in part, above ground.
They are found in various plant species:
- Epiphytic plants, i.e. those that grow by using another plant as a support without parasitizing it. These include orchids and some bromeliads such as tillandsias.
- Tropical marsh plants or those growing in mangroves.
- Some tropical trees such as banyan and other ficus trees.
- Temperate rainforest trees such as pohutukawa (Metrosideros robusta) in New Zealand.
- Climbing plants such as ivy or sumac vines, (Toxicodendron radicans)
- Parasitic plants such as mistletoe.
Contents
The Aerial Roots of Tropical Plants
In this case, in nature, the aerial roots of plants such as the false philodendron, namely the Monstera Deliciosa, are not destined to be buried like the so-called classic roots. They seek indeed to cling to trees or other large plants, so that the plant can have a support and evolve. It also serves to capture ambient humidity, which in a natural environment, i.e. in a very humid area such as a canopy, is obviously important.
In an apartment, it is not necessarily the same. A little humidity is welcome for us humans, but no more. Otherwise, the consequences are rarely nice, stains on the walls and so on! We thus do without it very gladly. Also, we might as well leave the aerial roots of our beautiful tropical plants, make their life and try to capture the humidity they can and want.
Of course, these aerial roots can and know very well how to take root in the ground if they have easy access to it. So they function like other roots, when the environment allows it and if their length allows it. Same in water.
The epiphytic roots of orchids
Orchids with epiphytic characteristics give a beautiful root cap, they have a white velamen that surrounds and protects the true root.
The velamen (whitish silver veil) protects and envelops the root from drying out. The root absorbs moisture from the air and nutrients through rainfall runoff on the trunks and bark of the trees.
Aerial roots also help create photosynthesis.
The roots of an epiphytic orchid, when sprayed, take on the appearance of a well green and swollen root.
In the case of drying out, velamen is created and protects (white veil) the aerial root because the cell walls thicken the veil which act like a sponge, are full of air and no longer water.
Often orchids are monopodial with single shoots, or sympodial with several shoots.
Monopodial orchids grow tall, otherwise sympodial orchids are bushier.
Many orchids form pseudobulbs at the base of the stems; it is a reserve organ resembling a spherical or oval, flattened or thick bulb.
They serve to store water and nutrients, their role is to ensure the nutrition of the young stem so that the roots can form.
Frequently, old pseudobulbs no longer bear leaves.
The pseudobulb allows the orchid to survive in drier periods.
Sympodial orchids that do not form pseudobulbs (e.g. phalaenopsis) have fleshy roots instead.
Phalaenopsis have more compact, thicker and fleshier leaves to create water and nutrient reserves.
The foliage is often shiny because phalaenopsis have a waxy layer that protects them from drying out.
Cut the aerial roots?
It is not recommended. Some Monsteras have very few aerial roots. It depends on the plants. Others, on the other hand, have a lot of them and it can seem unsightly.
When the aerial roots are or become too numerous and too cumbersome, which is quite understandable when you are in a small space such as an apartment etc… It is quite possible to stake or guide them. All that is needed is to handle them gently and, for example, to attach them to one of the main branches of the Monstera. You can also guide them to the soil of the pot or the water of your container if your Monstera (or cutting) grows in water.
The aerial roots can also be delicately tied together when several are close together and go in all directions. This prevents them from spreading everywhere around your plant and being accessible for example to your young children or pets such as your cat. The Monstera deliciosa being considered toxic, you might as well avoid inconveniences and disappointments.
The aerial roots are therefore an integral part of the plant. Cutting them will probably not kill a strong and healthy plant. But it will clearly not help it either. At best, nothing will change. However, since these roots can be controlled, why deprive our beautiful plants of them?
Cultivate and maintain Monstera deliciosa
A luminous exposure for beautiful leaves
The Monstera deliciosa likes light exposure but without direct sun, as in its original tropical forest where it launches its long lianas to the trees while being protected from the sun. On the other hand, if it is placed in a too dark place, the leaves will be smaller and less cut.
Regularly clean the leaves of the Monstera deliciosa with a damp cloth so that they keep their shine.
A watering without excess and fertilizer inputs
Watering should be regular but not excessive. Avoid letting the water stagnate in the saucer because the roots rot easily. Like most plants with XXL foliage, Monstera is greedy. Apply regular “green plant” fertilizer between April and September to promote healthy, shiny foliage.
Gentle heat and humidity for optimal growth
The Monstera deliciosa has a continuous growth with temperatures between 13°C and 25°C. The hygrometry can be improved by regular basins of the foliage. It is hardy enough to be grown in a veranda kept frost-free but growth will be interrupted during the winter.
Watering will then be very reduced. It should be noted that it is cultivated in the open ground in certain very protected places along the coast.
The foliage can be basined with a non calcareous water to compensate for the drying atmosphere of heated interiors.
A possible but rare flowering
The bloom is rare in apartment but occurs rather regularly in greenhouse or veranda. The inflorescence of cream color resembles that of Arum. The developing fruit should not be eaten before complete ripening because of its high content of oxalic acid.
Summary
The aerial roots are roots that are characterized by growing above ground level; they are not, therefore, buried in the substrate, but generally require a surface to be fixed (unlike the stem which is a completely aerial organ).
They can occur in various species of plants, including epiphytes such as orchids, tropical trees, in coastal swamps such as mangroves, various species of fig trees, temperate forest (Metrosideros robusta and Pohutukawa or M. excelsa), New Zealand trees, in species of vines such as Hedera helix and in poisonous and irritating ivy (Toxicodendron radicans).
