How to take cuttings that root

Most cuttings that fail to root don't die from a bad cut. They die from what happens in the next sixty seconds, or the next four days, and the failure is nearly always one of five things: too much leaf sent into shock, a stem left exposed to air too long before it drank, stale hormone, a medium that never dried between waterings, or a dome pulled too soon. Get the sequence right and a home grower with no special equipment should expect most cuttings rooted within 7–14 days.

1. Step 1

   Select a healthy branch

   Actively vegetating, 2–4 weeks since the last topping or stress

2. Step 2

   Cut at 45°, just below a node

   10–15 cm, at least two to four nodes

   10–15 cm45°
3. Step 3

   Strip the lower leaves

   Remove leaves from any node that will sit in the medium

4. Step 4

   Dip in rooting hormone

   Fresh IBA, applied immediately before insertion

5. Step 5

   Insert into pre-moistened medium

   Firm contact, no air gap at the base

6. Step 6

   Cover with a humidity dome

   90%+ RH, low light, 22–25 °C

   90%+ RH

Pick a branch that wants to root

A cutting only ever performs as well as the tissue you take it from. Look for a lower or mid-canopy branch that's actively growing: new leaf pairs opening, internodes still extending, rather than the oldest, woodiest growth near the base of the plant or a tip that's still recovering from a recent topping. Two to four weeks since the last topping, defoliation or nutrient problem gives the mother plant time to rebuild the carbohydrate reserves the cutting will live on before it has roots of its own.

Avoid a branch that's flowering or about to flower: it's hormonally committed to a different growth programme and roots more slowly and less reliably than vegetative growth. And if a mother plant has looked off in the last month (pale, stunted or distorted new growth with no obvious feed or pest cause), don't take cuttings from it until you've checked why; see testing your plants for viruses and viroids before you propagate a problem alongside the cutting.

The cut: length, angle and where on the stem

Take 10–15 cm (4–6 in) of stem carrying at least two to four nodes — enough to bury a couple of nodes in the medium, where roots actually form, while leaving enough stem above ground to support the leaves you keep. Cut at roughly 45°, just below a node, using a sterile blade or scalpel: the angled face gives more surface area for water uptake than a flat cut, and cutting close to a node uses the tissue with the highest concentration of the cells that go on to form roots.

In the one controlled trial on cannabis stem-cutting propagation, cuttings of almost exactly this length (about 13 cm), taken from either the upper (apical) or lower (basal) part of the plant, rooted equally well: cutting position on the stock plant made no measurable difference to rooting success or root quality ^[1]. If your mother plant is short on vigorous material, that's useful: you don't need to hunt for a "better" part of the branch, just a healthy one.

Strip the leaves from any node you'll bury, so nothing sits rotting under the medium surface.

Why trimming leaf tips is the wrong kind of pruning

Plenty of grow guides tell you to cut the biggest fan leaves back by about half, to reduce transpiration load while the cutting has no roots to replace lost water. It's an understandable instinct, but it isn't what the evidence shows.

So: keep two to three leaves whole, leave their tips alone, and don't panic if a broad-leafed cultivar looks like a lot of foliage for a rootless stem. Under the high humidity a dome provides, transpiration stress is rarely the limiting factor these guides assume it is.

From blade to medium in under a minute

Two things can ruin an otherwise good cutting before it ever reaches the medium, and both are about speed and cleanliness rather than skill.

First, the blade. Soak or wipe it with a fresh 10% solution of household bleach (5.25% sodium hypochlorite), leave it wet for at least two minutes, then rinse, between every mother plant you cut from, not just between rooms or grows. Isopropyl alcohol is not a substitute: tested against hop latent viroid in infected sap, 70% ethanol had no effect on the viroid even after ten minutes of contact, while 10% bleach for two minutes degraded it completely ^[2]. Hop latent viroid, the pathogen behind most unexplained yield and potency loss in cloned cannabis, spreads in infected sap carried on cutting tools and causes no visible symptoms in many infected plants, so a bleach-cleaned blade, not an alcohol-wiped one, is the cheapest insurance you have against carrying it from one plant into your whole propagation tray ^[3].

Second, speed. A cut stem left exposed to air for more than a few seconds to a minute can draw air into the xylem, the tissue that will carry water up the stem, and once that channel holds an air pocket, the cutting can't take up water even after you've potted it. Cut cleanly, then either recut the stem under water or get the base wet again within seconds; don't lay finished cuttings on a bench while you deal with the next branch ^[4].

Apply rooting hormone to the bottom 3–5 cm of stem immediately before you insert it, not before you finish prepping a whole batch. A synthetic IBA (indole-3-butyric acid) gel outperforms plant-derived "organic" rooting extracts by a wide margin: in the same trial, cuttings dipped in 0.2% IBA gel rooted at 84%, against 40% for a willow-extract gel, and produced markedly better root systems (a root-quality score of 1.6 versus 1.0) ^[1]. Concentrations, and powder versus gel versus liquid formulations, are covered in rooting hormones: IBA concentrations and forms — use whichever form that article recommends, but use it fresh and use it fast.

The dome for the first four days, then the taper

Insert the treated stem into a pre-moistened medium (rockwool at around pH 5.5 is the most common choice at home), firmly enough that there's no air gap around the stem base. Cloning media are compared properly in cloning media compared; whichever you choose, pre-moistened and firm contact matter more than the material itself.

Dome RH, days 0–4

90%+

taper from day 5

Light

100–200µmol·m⁻²·s⁻¹

low, not dark

Temperature

22–25°C

day and night

Hold relative humidity at 90% or higher for the first four days, while the cutting has no roots and depends on its leaves absorbing water directly from saturated air. Keep light low: 100–200 µmol·m⁻²·s⁻¹ is enough for a rootless cutting and won't drive more transpiration than the leaves can handle. Hold temperature at 22–25 °C; root-zone temperature matters more than air temperature once callusing starts, so a heat mat under the tray is worth more than turning up room heat. From around day 5, start venting the dome for a few minutes a few times a day, and taper humidity down over the following 7–10 days as roots take over from leaves as the plant's main route for water.

As a worked example of the whole sequence: in the published cannabis trial, cuttings were held at 95% RH for days 0–4, stepped down to 80% for days 5–8 and 60% for days 9–12, at a constant 24 °C, under a light schedule stepping from 50 to 115 µmol·m⁻²·s⁻¹ over the same 12 days. Cuttings treated with IBA under that regime reached 84% rooting success by day 12 ^[1]. Your setup doesn't need to match those exact numbers, but the shape (high and steady, then a gradual step down as roots form) is the part worth copying. Full detail on targets by growth stage is in clone environment: humidity, light and temperature targets.

What you should see, and when

By day 3 to 5, the cut end should callus over: a pale, slightly swollen ring of undifferentiated tissue, not an open wound any more. That's the raw material roots form from, not roots themselves, so don't disturb the cutting to go looking for it. From around day 7 onward, check the drain holes of the tray or the sides of a clear cube for the first white root tips; in the cited trial, researchers checked daily from day 7 and harvested the whole batch at day 12, once more than half of all cuttings showed visible roots ^[1]. Most home growers see cuttings genuinely ready to transplant, meaning a visible white root system and not just tips, somewhere between day 10 and day 14, though the exact day moves with cultivar, hormone freshness and how consistently you've held humidity and temperature. Treat these as ranges to plan a propagation schedule around, not deadlines a healthy cutting has to hit.

When it isn't working: three checkpoints and the fix

Most propagation problems show up as one of three patterns. Match yours against the likely cause before you change anything else.

If a whole batch fails the same way, look for one shared cause: the same mother plant, the same tray, or the same hormone bottle, before you assume the technique itself is wrong. A single mother that repeatedly gives cuttings that won't root, even when everything above is right, is covered in why cuttings don't root.

Once roots form, before you pot up

A cutting with visible white roots and new leaf growth is ready to move into its next container, not necessarily its final one — potting a small root system straight into a large pot leaves wet medium the roots aren't yet using, which invites the same rot problems as an overwatered cutting. Step up pot size gradually, and hold off on full-strength feed until you see active new growth, the sign that roots are actually taking up nutrients rather than sitting in solution around them.

Keep a record of which mother each batch came from and how it rooted. Over several rounds that record tells you more about a mother plant's cloning vigour than any single cutting can, and it's the first thing worth checking if a normally reliable mother suddenly stops giving you cuttings that root.