Reading orchid roots through a clear pot

The single most useful thing about a clear orchid pot is that it turns watering from guesswork into observation. Once you can read what the roots are telling you, most orchid problems become obvious weeks before the leaves show anything.

The colours

Bright green — a healthy root that has just been watered. Velamen full of water is translucent, and the green of the root core shows through.

Silvery white or pale grey — a healthy root that is dry. This is not a problem; it is the signal that the plant is ready for water. Most orchids die from being watered while the roots are still green.

Brown and firm — usually fine. Older roots go tan with age, and some species are naturally darker. Firm is the operative word.

Brown, soft, mushy or hollow — dead. Squeeze gently: a rotted root collapses, and the outer layer slides off leaving a thread. These come out at the next repot.

Bright green tip on a silvery root — the best sign there is. Active growth.

Thirst versus rot

Both produce a limp, wrinkled leaf, which is why people water a rotting orchid and finish it off.

The roots tell the two apart immediately.

Wrinkled leaves plus silvery, firm roots — the plant is thirsty. Water it.

Wrinkled leaves plus brown, soft roots — the plant cannot take up water because the roots are dead. Watering makes it worse. This one needs repotting and the rotted roots removed.

The leaves look the same in both cases. That is the entire argument for a clear pot.

Condensation as a moisture gauge

Look at the inside wall. Heavy condensation means the medium is still holding water. Clear glass with silvery roots means it is dry.

This is more reliable than pushing a finger into the bark, which tells you only about the top inch — and the top inch dries first while the bottom stays wet.

Weight works too: lift the pot. A watered orchid is noticeably heavier, and after a few weeks you will know the difference without thinking.

Aerial roots

Roots growing up and out of the pot into the air are normal. Phalaenopsis is an epiphyte and in the wild most of its roots are in the air.

Do not cut them off if they are firm, and do not force them into the pot — they will snap. Leave them.

Aerial roots that are silvery are simply dry. If most of the roots in the pot are dead and only the aerial ones are alive, that is a plant telling you the medium has been wet too long.

What healthy looks like over a year

New roots appear from the base of the plant, initially as green nubs. They extend with a green growing tip, and mature into thicker roots that go silvery between waterings.

A plant producing new roots is a plant that is happy, whatever the leaves are doing. A plant that has produced no new roots in a year is not.

What to do about rotted roots

Unpot the plant. Remove all the old medium. Cut away every soft or hollow root with clean scissors, cutting back to firm tissue.

Sterilise the scissors between plants — rubbing alcohol on the blades.

Repot into fresh medium in a pot sized to the remaining roots, which will usually be smaller than the pot it came out of. Then water sparingly until new roots appear.

A plant with very few roots left can be kept in a humid spot with the medium barely damp until it recovers. Do not compensate for lost roots by watering more.

Watering by observation

The whole method, in four lines:

• Roots green, condensation on the wall — do nothing.
• Roots silvery, wall clear, pot light — water thoroughly until it runs out of the slots.
• Never leave the pot standing in water.
• Never water on a schedule. Water on the roots.

In south Florida this varies enormously between the dry season and the wet, which is precisely why a fixed schedule fails here.

Clear pot inside a decorative one

You can have both. Keep the plant in the clear slotted pot and drop it into a ceramic cachepot for display. Lift it out to water, let it drain, put it back — and lift it out any time you want to look at the roots.

What you must never do is let water stand in the outer pot.

Where to look

Clear slotted pots in every size, singly and in assortments, are on the clear slotted orchid pots page. Ceramic outers with real drainage are at ceramic and self-watering pots, nursery pots for growing on at nursery pots and tools, and supports at plant stakes and supports and orchid clips.