Springtails
Collembola
Pinhead creatures that spring away when you disturb damp compost. They eat fungi and decay, not plants, and a lot of them means healthy soil.
How to know it
A soft, wingless, pinhead-sized animal, white, gray or dark, that leaps several centimeters when disturbed using a forked spring folded under its abdomen. Found in damp compost, in the drainage tray of a houseplant, on the surface of an overwatered pot, or in vast numbers on snow in late winter — the snow fleas.
What you'll see
- A cloud of tiny hopping specks when you water a pot or turn damp compost.
- Gray or white dots on the surface of over-wet potting compost.
- Numbers in a seed tray or a propagator that has been kept saturated.
- Occasional very fine pitting on the roots of a seedling in a saturated tray — the only damage they do.
- A dark dusting on snow or on a puddle surface in late winter.
Where it comes from
They feed on fungi, algae, bacteria and decaying plant matter, and are one of the most abundant animals in any healthy soil — hundreds of thousands per square meter is normal. They breed continuously wherever it is damp, and they do not bite, sting or carry anything.
Constant damp is the only requirement. Overwatered houseplants, saturated seed trays, damp compost heaps and mulched beds all carry them, and they vanish as soon as things dry out.
Dealing with it
- Let the compost dry out between waterings. That is the whole treatment, and it works within days.
- Empty standing water from drip trays and saucers.
- Improve drainage and airflow in a propagator or a frame.
- Repot a houseplant into fresh, free-draining compost if the numbers bother you.
- Do not use insecticide. They are not damaging anything and they are a sign the soil is alive.
Keeping it out
- Water pots when the surface has dried rather than keeping them permanently wet.
- Use a free-draining potting mix and pots with proper drainage.
- Ventilate propagators and frames.
- Keep the compost heap away from the seedling bench if the sight of them is unwelcome.
- Take large numbers in a garden bed as good news; they are part of what makes soil work.
What it goes for
Nothing, in practice. Very occasionally seedling roots in a saturated tray.
Who hunts it for you
- CentipedesChilopoda Flat, fast, one pair of legs to a segment — and a predator, unlike the slow round millipede it is constantly confused with. It hunts slugs, cutworms, springtails and woodlice by night under mulch and stones. Learn the difference and leave this one alone.
- Salamanders & newtsCaudata Damp-loving hunters of slugs, worms, woodlice and beetle larvae that spend the day under a log or a stone and work the beds at night. Companions to the toads: they want the same damp shade, the same log pile, and the same absence of slug pellets.
See also
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com