# Can I root clones in plain water?

> Yes. Cannabis cuttings can root in plain water, usually in 10–21 days, but results are less even than in a plug or aeroponic cloner. Keep the water dark, at 20–24 °C (68–75 °F), change it every 2–3 days, and add an air stone if you can. Move them to medium when roots are 2–5 cm (1–2 in) long; long water roots transplant badly.

- Canonical: https://genetixbay.com/knowledge/answers/rooting-clones-in-water.html
- Topic: Cloning and mother plants · Type: How-to
- Evidence: Grower practice · Status: Draft: awaiting expert review
- Full article: [Clone-only cuts and how to preserve them](https://genetixbay.com/knowledge/breeding/clone-only-preservation.md)
- Also asked as: Can I clone in a glass of water? | Water cloning cannabis | Cuttings in a cup of water | Do water roots survive in soil?
- Updated: 2026-10-31 · Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay Knowledge Base (genetixbay.com/knowledge)"

## Short answer

Yes. Cannabis cuttings root in plain water, usually in 10–21 days, though less evenly than in plugs or an [aeroponic](https://genetixbay.com/knowledge/glossary/aeroponics.md) cloner. Keep the water dark, 20–24 °C (68–75 °F), changed every 2–3 days, and [transplant](https://genetixbay.com/knowledge/glossary/transplanting.md) at 2–5 cm of root. *Grower practice*.

## Why

Cannabis roots readily, so a cut stem in water will often form roots without any medium.

Oxygen is the limit. Still water holds little oxygen and loses more as it warms; oxygen management is central to keeping [Pythium](https://genetixbay.com/knowledge/glossary/pythium.md) out of hydroponic roots [3].

Warm, stagnant water breeds rot. Pythium and [Fusarium](https://genetixbay.com/knowledge/glossary/fusarium-wilt.md) both infect cannabis roots in hydroponic systems [1], and a brown, slimy stem base in a glass is the same problem.

Air in the [root zone](https://genetixbay.com/knowledge/glossary/root-zone.md) helps rooting in any medium. In one cannabis trial, cuttings in an airy peat-perlite mix rooted best, while [rockwool](https://genetixbay.com/knowledge/glossary/rockwool.md) held at full water capacity, with less [air space](https://genetixbay.com/knowledge/glossary/air-filled-porosity.md), rooted worst [2].

Water roots are a different shape. They are thick and brittle and must regrow fine roots once moved to soil or [coco](https://genetixbay.com/knowledge/glossary/coco-coir.md).

## The numbers

| Item | Target |
|---|---|
| Water temperature | 20–24 °C (68–75 °F) |
| Water change | Every 2–3 days |
| Depth | Bottom 3–5 cm (1–2 in) of stem only |
| Light | 50–150 [µmol/m²/s](https://genetixbay.com/knowledge/glossary/ppfd.md), 18–24 h |
| Time to roots | ~10–21 days |
| Transplant at | 2–5 cm (1–2 in) roots |

## What to do

1. Use a dark or foil-wrapped glass so algae don't grow.
2. Fill with clean, room-temperature water; add an [air stone](https://genetixbay.com/knowledge/glossary/air-stone.md) if you have one.
3. Stand the fresh-cut stem 3–5 cm deep; keep leaves dry.
4. Change the water every 2–3 days.
5. Pot into a light, moist mix at 2–5 cm of root, then keep humidity high for 3–5 days.

## Common mistakes

- Clear glass in a sunny window.
- Never changing the water.
- Leaving roots to grow 15 cm long before potting.
- Submerging leaves.

## Related

- Full article: [Clone-only cuts and how to preserve them](https://genetixbay.com/knowledge/breeding/clone-only-preservation.md)
- [Best medium for rooting clones](https://genetixbay.com/knowledge/answers/best-medium-for-rooting-clones.md) · [When to transplant clones](https://genetixbay.com/knowledge/answers/when-to-transplant-clones.md)
- [Root rot (Pythium)](https://genetixbay.com/knowledge/diseases/root-rot-pythium.md)
- Terms: [aeroponics](https://genetixbay.com/knowledge/glossary/aeroponics.md) · [dissolved oxygen](https://genetixbay.com/knowledge/glossary/dissolved-oxygen.md)

## Follow-up questions

**Why do water-rooted clones struggle after transplanting?** Cannabis roots grown in water are adapted to it: thick, brittle and short of the fine root hairs that work in soil or coco. Moved into a medium, they need time to grow new roots, so the clone stalls or wilts for a few days. Transplant early, when roots are 2–5 cm (1–2 in) long, into a light, moist mix, and keep humidity high for 3–5 days.

**How often should I change the water for clones?** Change the water for cannabis cuttings every 2–3 days, or sooner if it goes cloudy or smells. Still, warm water loses oxygen and grows bacteria and root-rot organisms such as Pythium, which turn stems brown and slimy. Use clean, room-temperature water, keep the container dark, and an aquarium air stone makes a real difference.

**Is an aeroponic cloner better than a glass of water?** Usually, yes. An aeroponic cloner sprays the stems with fine water so they sit in humid air rather than standing water, giving roots far more oxygen. Many growers find it roots cannabis cuttings faster and more evenly than a glass. The catch is hygiene: clean the reservoir between batches, keep it below about 24 °C (75 °F), and watch for slimy stems.

## Sources

1. Punja ZK, Rodriguez G, 2018. Fusarium and Pythium species infecting roots of hydroponically grown marijuana (Cannabis sativa L.) plants. Canadian Journal of Plant Pathology 40(4):498–513. https://doi.org/10.1080/07060661.2018.1535466
2. Hwang SJ, Collado CE, Hwang HS, Yun JH, Hernandez R, 2026. Impacts of commercial and custom substrates on rooting and morphology of Cannabis sativa 'Suver Haze' stem. HortTechnology 36(3):429–434. https://doi.org/10.21273/HORTTECH05810-26
3. University of Kentucky Cooperative Extension, E706 (hydroponic Pythium and oxygen management). https://greenhousehort.ca.uky.edu/sites/greenhousehort.ca.uky.edu/files/E706.pdf