Pests

Springtails

Tiny jumping specks in damp soil that alarm people but almost never harm a plant.

What you'd see

Minute white, grey or purple specks on the soil or in the saucer that jump when disturbed
Clouds of them floating on water after a heavy watering
No leaf damage

Where to look

Wet potting mix, saucers, and terrariums.

How it spreads

Present in most healthy soils already; they become visible when moisture and decaying matter are high.

Is it really this? Look-alikes

Fungus gnat larvae — Gnat larvae are worm-like and do not jump.
Root mealybugs — Root mealies are waxy white and do not move quickly.

What's going on

Springtails are ancient soil animals that eat fungi, algae and decaying matter. They are part of the clean-up crew and are common in terrariums on purpose.

A population boom means the soil has been consistently wet and rich in decaying organic matter.

Why?

This entry is here to stop you reaching for a spray. Springtails are a moisture indicator, not a pest — the useful response is the same as for fungus gnats: let the mix breathe.

Grandmother's remedies

What people have always done — with an honest note on each.

Let the soil dry
Water only when the top few centimetres are dry.
Verdict: Solves the boom. They will still be present in small numbers, and that is fine.

Modern remedies

What growers and extension services reach for today.

Nothing
Adjust watering; no treatment needed.
Verdict: Honestly the best modern advice, too.

Honest verdict

You do not need to kill springtails. If they bother you, dry the mix out a little and they retreat.

Prevention

Water by soil check
Empty saucers after watering