How to Quarantine New Plants and Clones

3 min read

A new cannabis clone isolated under a small light for quarantine inspection

The Collector got offered a free clone from a mate’s grow — healthy-looking, vigorous, good genetics. Straight into the tent with everything else, because why wouldn’t it be fine? Within a week, every plant had spider mites. The clone looked clean to the naked eye, but there were mite eggs on the leaf undersides, invisible without magnification. It was a Trojan horse: beautiful outside, an army inside. That’s how most indoor infestations actually start — not from the air, from something the grower carried in.

The short version:

  • Every new plant — clone, cutting, outside seedling — gets 7–10 days in isolation first
  • Keep it away from the main tent; inspect daily with a loupe
  • Check leaf undersides, stem nodes and the soil surface for pests and eggs
  • See anything? Treat it in isolation and only move it in once it’s clean
  • Same rule for second-hand gear — clean it before it enters the space

Want the full breakdown? Keep scrolling.

Why quarantine?

Because the naked eye can’t see what matters. Mite eggs, early-stage juveniles, aphids tucked on a new shoot — they hide on undersides and in nodes, and by the time they’re obvious they’ve spread. A clone from even a good grower can carry them. Quarantine gives the hidden stages time to reveal themselves where they can’t reach your crop, and gives you a window to deal with anything before it’s in among everything you’ve worked on. The Collector skipped the week and paid with a whole-tent infestation.

What’s the quarantine protocol?

Set up a separate space — a corner under a small light, or near a window if that’s all you’ve got — well away from the main tent. The new plant lives there for seven to ten days. Each day, inspect it properly: a jeweller’s loupe (DIG stock them for a tenner) over the undersides of every leaf, the stem nodes, and the soil surface. You’re hunting mites, eggs, gnats, aphids — anything. If you find something, treat it right there in isolation and restart the clock; don’t promote it to the main tent until it’s clean and any treatment cycle is finished. Only when it’s earned a clear week does it join the others.

Does this apply to equipment too?

Yes. The Importer bought a second-hand tent and inherited the previous grower’s mites along with the bargain. Anything coming from outside — used tents, pots, fans, tools — gets cleaned before it enters your space: a bleach or hydrogen-peroxide wipe, or isopropyl alcohol, and let it dry fully. Treat everything from outside as potentially carrying something until proven otherwise. It feels like overkill right up until the grow it saves.

FAQ

How long should I quarantine a new clone? Seven to ten days minimum, isolated from your main tent, with daily loupe inspections. Restart the clock if you find and treat anything.

What am I looking for during quarantine? Pests and eggs on leaf undersides, in stem nodes, and on the soil surface — spider mites, aphids, fungus gnats, whitefly. Magnification is essential; the early stages are invisible otherwise.

Do I need to quarantine seeds too? Seeds you germinate yourself are low risk. Quarantine is mainly for clones, cuttings and any plant from another grower’s space, plus second-hand equipment.

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