Orchid

Light and exposure

The orchid likes plenty of light, but never direct sun, which burns its leaves and leaves brown marks. The ideal here is an east-facing window or a south-facing window veiled by a light curtain. Light green leaves signal good light, dark green ones that it is lacking some.

Its aerial roots, grey and fleshy, turn green after watering: they photosynthesise too. It is normal that they spill out of the pot, do not try to bury them. A transparent pot is in fact recommended, it lets the light reach the roots and allows you to monitor their colour.

Watering

This is where most failures play out. The orchid does not want stagnant water. The good method is soaking: once a week, plunge the pot into a container of room-temperature water for ten to fifteen minutes, then let it drain thoroughly before putting it back in place. Never a full saucer under the pot.

Between two soakings, the substrate must dry out. Roots that go from green back to silvery grey tell you it is time to soak again. In winter, space it out to one soaking every ten to fifteen days. Too much water rots the roots, soft and brown: this is mistake number one, far more common than a lack of water.

Soil and repotting

Forget potting soil, it would smother the roots and rot them. An orchid is grown in a substrate based on pine bark, airy and coarse, sometimes mixed with sphagnum. This mix retains a little moisture while letting the air circulate around the roots, as on a tree trunk.

You repot every two to three years, in spring, when the substrate breaks down and packs together. Choose a barely larger pot, transparent and with a hole. Take the opportunity to cut off with a clean blade any soft, hollow or blackened root, and keep only the firm roots.

Temperature and humidity

The moth orchid is happy in our interiors, between 18 and 24 degrees during the day. It appreciates a small drop at night, a few degrees less, which reproduces its native climate. Below 15 degrees it sulks, and it tolerates no sharp cold: never leave it against a cold pane on a winter night.

The air in our heated homes in winter is very dry, which hardly suits it. Set the pot on a bed of damp clay balls, without the base sitting in water, or group your plants to create a more humid microclimate. Above all, avoid the direct proximity of a radiator, which dries out the foliage and makes the buds drop.

Pruning and upkeep

Routine care comes down to a few gestures. Wipe the dust off the leaves from time to time with a soft, damp cloth, remove the faded flowers as you go and monitor the colour of the roots through the pot.

The key move comes when flowering ends. Do not cut the stem right down. Spot the small swellings along the stem, the eyes, and cut just above the second eye from the bottom. Often, the plant sets off again from that eye and reflowers in the following weeks. If the stem yellows and dries out entirely, then cut it at the base.

Pests and diseases

The main pest of the orchid indoors is the mealybug, those small white cottony clusters nestled in the leaf axils and on the aerial roots. It weakens the plant and leaves a sticky honeydew. Dab each outbreak with a cotton bud soaked in methylated spirits and inspect the undersides of the leaves regularly.

The real trouble comes above all from excess water. Root rot, soft and brown, follows over-generous watering or a saucer that stays full. Soft black spots on the leaves betray a rot favoured by water stagnating in the heart of the plant: water the substrate, not the foliage.

Propagation

The moth orchid does not propagate easily at home, best to know it. The most accessible route is the keiki, a small offshoot that sometimes grows all by itself on a flower stem, with its own leaves and roots. Let its roots reach three to four centimetres, then detach it gently and repot it in fine bark.

Sowing from seed is a laboratory matter: the tiny seeds need a sterile medium to germinate, not realistic at home. For the amateur, then, you rely on keikis when the plant is willing to make them, and otherwise you keep and reflower the same plant year after year.

Month-by-month care calendar

Green Hub tips

• Never leave water in the saucer. Root rot from excess water kills more orchids than everything else combined.
• Do not bury the aerial roots. Grey and fleshy, they photosynthesise and live very well in the open air, it is normal.
• After flowering, cut the stem just above an eye and not right down: the plant often sets off from there and reflowers.
• When the days grow short, move it closer to the window and away from the radiator. Lack of light and dry air are its two enemies of the dark season.