How long do clones take to root?

Q: How long do clones take to root?

Most cannabis clones root in 7–14 days, with the first roots showing around days 7–12 at a medium temperature of 22–26 °C (72–79 °F), high humidity and gentle light. Cuttings in a cold medium, from flowering plants or without rooting hormone can take 2–4 weeks or fail. If nothing after 3 weeks, check medium temperature, wetness and the cutting's source.

Short answer

Most cannabis clones root in 7–14 days at a medium temperature of 22–26 °C (72–79 °F) with high humidity and gentle light. Slow or flowering cuttings can take 2–4 weeks. Supported by propagation trials.

Why

Trials show the timescale. Hemp cuttings at about 25 °C under 24-hour light were ready 12 days after sticking, once more than half showed roots ^[1]. Drug-type cuttings in a growth chamber were assessed after 9 days, with the best medium rooting 41% by then ^[2].

Medium choice changes the result. Rooting success ranged from 13% to 80% across media in one trial ^[1], and from 0% to 41% in another ^[2].

Hormone speeds it. IBA gel gave 2.1 times the rooting success of a willow-extract gel ^[3].

Warm roots grow faster. A cold plug slows callus and root formation more than cool air does.

The numbers

Situation	Typical time to roots
Vegetative cutting, IBA, 22–26 °C medium	7–14 days
No hormone	Slower, fewer rooted
Medium below ~20 °C (68 °F)	2–3 weeks
Cutting from a flowering plant	2–4 weeks, then re-veg
Ready to transplant	Several white roots 2–5 cm (1–2 in) out of the plug

What to do

Put a thermometer probe in a plug; aim for 22–26 °C.
Keep plugs moist but not wet.
Use IBA gel or powder on every cut.
Check from day 7 for root tips at the plug's sides or base; don't tug.
After 21 days with no roots and no callus, re-cut fresh.

Common mistakes

Pulling clones up to look.
Cold floors or windowsills.
Soggy plugs that rot the stem.
Cutting from plants already in flower.

Full article: Clone-only cuts and how to preserve them
How do I clone a cannabis plant? · When are clones ready to transplant? · Why are my clones wilting?
Terms: cloning · rooting hormone

Follow-up questions

Why is my cannabis clone not growing after rooting?

A newly rooted cannabis clone often sits still for a week or so while it builds roots and adjusts to lower humidity. If it stalls longer, the usual causes are too few roots when it left the dome, a soggy medium, low light, or no feed in an inert medium. Give it 150–300 µmol/m²/s and a light feed once roots show.

Why are my clones not rooting?

Cannabis clones usually fail to root because the medium is too cold or too wet, the cutting came from a flowering or stressed plant, or no rooting hormone was used. Aim for a medium temperature of 22–26 °C (72–79 °F), plugs moist but not soggy, and an IBA gel. Some cultivars simply root slower; give them three weeks before discarding.

Does a heat mat speed up rooting?

A heat mat can speed up cannabis rooting in a cool room by warming the medium toward 22–26 °C (72–79 °F), which matters more than air temperature. In a warm room it adds little and can dry the plugs or push the medium too hot. Put a thermometer probe in a plug and use a thermostat rather than running the mat flat out.

Sources

Campbell SM, Anderson SL, Brym ZT, Pearson BJ, 2021. Evaluation of substrate composition and exogenous hormone application on vegetative propagule rooting success of essential oil hemp (Cannabis sativa L.). PLOS ONE 16(7): e0249160. doi.org/10.1371/journal.pone.0249160

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. doi.org/10.21273/HORTTECH05810-26

Caplan D, Stemeroff J, Dixon M, Zheng Y. 2018. Vegetative propagation of cannabis by stem cuttings: effects of leaf number, cutting position, rooting hormone, and leaf tip removal. Canadian Journal of Plant Science 98(5):1126-1132. doi.org/10.1139/cjps-2018-0038