Watering an orchid mounted on cork

Mounting an orchid on a cork plaque means recreating how it lives in the wild. In nature, the vast majority of orchids do not grow in soil: they cling to tree bark, roots bare to the open air. They are called epiphytes.

This way of growing has one decisive advantage — root rot becomes impossible, since nothing holds water. And an equally clear constraint: it dries out fast. Very fast.

Why a mount changes everything

An orchid in a pot holds its moisture for a day or two, sometimes longer. The same plant on a mount can be dry in three hours in warm, dry weather.

The consequence is simple: you will not water less often, you will water a great deal more often. In exchange, drowning it becomes almost impossible.

Soaking: the reference method

Submerge the whole plaque — plant included — in a tub of room-temperature water for ten to twenty minutes. The roots and the sphagnum around them fill with water, and you can watch the roots turn green before your eyes.

Drain for a few minutes before hanging it back up. Never let water sit in the crown of the leaves, especially in the evening: that is the way in for bacterial rot.

This is the method we recommend for the main watering.

Misting: a supplement, not a watering

Misting wets the surface and raises the humidity of the air for a few minutes. It is useful between two soakings, in very dry weather, or in the morning in summer.

But misting does not hydrate a plant deeply. The classic mistake is misting daily in the belief that you are watering — the plant slowly dehydrates while the grower feels diligent.

How to know when to water: read the roots

This is the whole advantage of a mount: the roots are visible. They tell you exactly what the plant needs.

• Bright green — the root is full of water. Do not water.
• Silvery white — the velamen, the spongy layer around the root, is dry. Now is the time.
• Brown, soft, stringy — a dead root. It will not green up again.

Water by observation, not by the calendar. An orchid at a sunny window in July and the same one in November do not have the same needs — the calendar does not know that, the roots do.

How often, in practice

In an ordinary home, reckon on:

• Summer, dry air: soak every day or every second day, plus a misting in the morning.
• Winter, heating on: every two to three days — heated air is very dry, do not ease off.
• In a terrarium or humid case: once or twice a week is often enough.

These are starting points. The roots will settle it.

Which water

Rainwater, reverse-osmosis or demineralised water. In the wild, epiphytes receive water very low in minerals; hard water leaves whitish deposits on the roots and the cork, and eventually hinders uptake.

If tap water is all you have, let it stand overnight and rinse everything thoroughly from time to time.

Ambient humidity does half the work

The more humid the air, the less you water. A mount in a bright bathroom or a growing case needs vastly less attention than the same mount in an electrically heated living room.

If you find the watering rhythm unsustainable, it is not your watering that needs to change: it is the humidity of the air.

Which orchids suit this method

Miniatures and botanical species with small root systems are especially well suited: Gastrochilus, Schoenorchis, Haraella, many Bulbophyllum, and the Aerangis of Madagascar.

See our selection of orchids mounted on cork, ready to hang, and our miniatures.