How to make roots on cannabis cuttings
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Propagation · Cloning

How to make roots on cannabis cuttings

This guide shows you how to make roots on cannabis cuttings correctly each time. It gives a new grower all the steps, from the selection of a mother plant to a clone that you can transplant in 14 days.

Propagation9 diagramsCitations · 7 sources~12 min read
In this paper
01 Purpose and scope02 Definitions03 Evidence and limitations04 Select and cut shoots05 Rooting hormone and propagation cubes06 Dome, humidity, temperature and light07 14-day cloning procedure08 Troubleshooting09 Expected results and limitations10 References
01 · Start here

Purpose and scope

A clone is a cutting from a plant. The cutting makes roots and becomes a new plant with the same genetics as the first plant. Cloning does not use flowers or seeds. You make roots on a piece of stem, and you do not germinate a seed.

Cloning gives each plant in a batch the same genetics as a known plant with good results. This plant is the mother plant. The same genetics gives the same speed of growth, the same yield and the same chemical properties. As a result, all the plants in the batch complete the crop cycle at the same time. The yield is the same as the yield of the last batch. Thus almost all commercial growers use clones and not seeds.

In a propagation room that operators control correctly, the rooting rate is frequently approximately 90 percent or more[1]. Operators use this rate as a target. You can transplant the cuttings after approximately 10 to 14 days[3].

From mother plant to transplant1Motherplant kept ingood growth→2Take cuttingcut at 45° belowa node→3Stick in cubein a humiditydome→4Roots emergeday 7–14→5Transplant~day 14
Figure 1. The figure shows the five steps of the full procedure. You can see roots between day 7 and day 14. You can transplant the clone at approximately two weeks.[3]
Who this is for

This guide is for a grower who wants to make a copy of a plant with the traits that the grower wants. The grower also wants a batch in which all the plants are the same, each time. Use the light acclimation guide with this guide to move new clones into stronger light. Use the IPM hygiene guide with this guide to keep the room clean.

02 · The terms

Definitions

This guide uses these six terms many times. Make sure that you know the terms before you continue.

NodeThe point on a stem where the leaves and the side shoots attach. New roots and new growth start at the nodes. Thus you cut the stem near a node, and the new roots start at the node.
Mother plantA plant that you keep permanently in vegetative growth (growth of leaves). The plant does not make flowers. You keep the plant only to supply cuttings.
Cutting / cloneThe shoot that you cut from the mother plant to make roots on it. After you cut the shoot, "cutting" and "clone" are two names for the same shoot.
Rooting cubeThe cube of rockwool or peat that holds the cutting while the cutting makes roots. The cube holds water and air around the stem.
DomeThe transparent plastic lid that holds the humidity in the air above the tray. A burp is a task in which you lift the dome for a short time. The task replaces the air in the dome with new air.
Hardening offThe procedure in which you open the dome vents in stages and then remove the dome. The clones then adapt to the usual air of the room before the transplant.
Parts of a prepared cutting1Nodewhere roots willstart→2Internodestem betweennodes→345° basal cutnew, directlybelow a node→4Lower leaves removedto keep morewater→5Fan tips trimmedto ~50–70%→6Stem in cube1.5–2.5 cm(0.6–1.0 in)deep
Figure 2. The figure shows a cutting that you prepare for the cube. Cut the stem at an angle directly below a node, and make sure that the end is clean. Remove the bottom leaves. Cut the tips of the large fan leaves. Put the stem in the cube to the correct depth.
Quality of the information

Evidence and limitations

Three types of information

We want each paper to be correct. Thus we examine each paper for information that is not solid. This information comes from the view of one grower, from a small number of sources, or from grower methods that have no controlled test. We identify this information, and we do not show it as solid.

Frequently there is no paper for the decision that you must make. Then we use the reports of other growers and the methods that work in the rooms that we know. This information can help you, but it is not the result of a laboratory test. Use the methods that work for your plants, for your room and for your meters. If a table does not agree with your crop, use the data from your crop and record the difference.

Solid
Tests of plants, specifications or many sources that agree show that the information is correct
  • A clone has the same genetics as the mother plant. A somatic mutation, which is not frequent, can cause a difference.
  • High humidity and a low light intensity decrease the stress on a cutting until the cutting makes roots.
  • Dirty tools and wet media where the water does not move increase the risk of soft rot and of pathogens.
Grower method
Many growers use this method in their rooms. Start with it, then change it for your room.
  • Procedures with IBA gel or powder, and procedures to open the dome vents, in commercial rooms for propagation.
  • The target for a room with correct control is a rooting rate of 90% or more. Genetics do not make sure of this rate.
  • Apply a feed with a low EC after the roots show. An EC that is too high causes damage to soft cuttings.
Weak
The view of one grower, a small number of sources, one test, or a method that works in one room
  • Air embolism as the one primary cause of soft stems. Drying of the cutting usually has the largest effect.
  • Tables with one number of days to roots that ignore the cultivar and the environment.

If you find an error, make a report. We will correct it. Make the report on GitHub, with the name of the paper and the information that is incorrect. If you have a source, include it: Make a report of an accuracy problem. The regulations, labels and licenses of your area always override each procedure in these papers. The label weak in a paper shows the points where the risk of an error is highest.

03 · Selecting and cutting

Select and cut shoots

A good clone starts with a good shoot. Select vertical shoots from the top and middle parts of the canopy. Each shoot must be a minimum of 3 mm (0.1 in) thick and 15 cm (6 in) long. Thicker shoots that receive good light have larger energy reserves. These shoots make roots more quickly than thin shoots in the shade of the inner canopy[2]. The thickness of the shoot and the color of the leaves are accurate indicators of the root growth of the cutting[2].

Apply sufficient water to the mother plant on the day before you cut the shoots. Then the cuttings are full of water and have turgor, and tissue that shows wilt does not easily make roots. Use a sterilized blade. At the start of the light cycle, cut each shoot at 45° directly below a node. Put each cutting immediately in a container with a weak solution. Make sure that the surface of the end is clean and that the end does not stay in the air.

Cut at 45° and keep air out of the stem
  • If you cut the stem at 45°, the surface at the end of the stem is larger than if you cut the stem flat. Thus more cells can become root cells.
  • If the end of the stem dries in the air, a bubble of air goes into the stem. This bubble is an air embolism, and it stops the flow of water up the stem. Keep the end wet from the time that you cut the stem.
  • Sterilize the blade between mother plants. Thus you do not move disease from one plant to the next.[7]
Position of the shoot on the mother plantTypical rooting results. Hard shoots with good light at the top and middle make the most roots.025507510092% rootUpper-mid (best)58% rootLower interior70% rootSoft tip growth
Figure 3. Vertical shoots from the top and middle of the canopy, in good light, make roots at the highest rate. Weak shoots in the shade of the inner canopy have much lower rates.[2]
04 · Hormone and cube

Rooting hormone and propagation cubes

A cutting has no roots at the start. Thus you apply a rooting hormone to start the production of roots. A plant hormone is a chemical signal that gives instructions to the cells. The active ingredient in rooting hormones is usually IBA (indole-3-butyric acid), an auxin, which is a type of plant growth signal[4]. In the stem, the plant changes IBA to IAA, and IAA is the signal that starts root growth[5]. A rooting hormone is available as a gel or as a liquid.

Cut the stem again at 45° immediately before you put the cutting in the cube. Thus the end of the stem has new tissue. Apply rooting hormone gel to the bottom 1–2 cm (0.4–0.8 in) of the stem. Put the stem 1.5–2.5 cm (0.6–1.0 in) deep in a soaked cube. Push the cube lightly against the stem, but do not compress the cube. To do the lift test, lift the stem carefully, and make sure that the cube moves up with the stem.

  1. 1
    Soak the cube first
    Soak the rockwool or peat cubes in clone feed for a minimum of 15 minutes. Let the cubes drain freely. Do not compress the cubes to remove the water. If you compress a cube, you remove the air from the cube.
  2. 2
    Cut the stem again
    Cut the stem again at 45° immediately before you put the cutting in the cube. Thus the tissue at the end is clean and has no air embolism.
  3. 3
    Apply hormone
    For gel, put the bottom end of the stem approximately 1–2 cm (0.4–0.8 in) deep in the gel. For a liquid or alcohol hormone, soak the bottom end of the stem for approximately 30 seconds.
  4. 4
    Put the stem in the cube and do the lift test
    Put the stem 1.5–2.5 cm (0.6–1.0 in) deep in the cube. Lift the stem carefully. The cube must move up with the stem.
Put the cutting in the cube in less than 30 seconds

After you cut the stem for the last time, put the cutting in the cube in approximately 30 seconds or less. When the stem end is in the air for a longer time, the risk of an air bubble increases. The bubble stops the uptake of water, and the cutting stops its growth.

Hormone concentration and rooting (typical IBA effect)Rooting increases with the IBA dose to a maximum. A higher dose causes damage to the stem, and rooting decreases.405570851000 (none)lowmediumhightoo high% rooted
Figure 4. If the quantity of hormone is not sufficient, root growth is slow. Too much hormone causes damage to the bottom of the stem. The manufacturer mixes a rooting hormone gel to a concentration in the range for good rooting.[4]
05 · Environment

Dome, humidity, temperature and light

A cutting with no roots cannot pull water up the stem. Thus the cutting gets water from the humidity of the air until the roots start. The dome holds the humidity around the cutting. As a result, water goes directly from the air into the leaves while the stem makes roots.

Keep the air temperature at approximately 24–26°C (75–79°F). At the start, keep the humidity high (85–95% RH) in a closed dome. Then decrease the humidity in steps when the roots become longer[3]. Put a heat mat below the tray to keep the cube temperature at 22–24°C (72–75°F). The cube temperature has more effect on the speed of root growth than the air temperature has[6].

VPD shows how much the air pulls water from the surface of a leaf. Air with less humidity and a higher temperature pulls more water from the leaf. When the VPD is higher, the surface of a leaf dries more quickly. Keep the VPD low (0.3–0.5 kPa) while the cuttings have no roots. Then increase the VPD in steps when the roots become longer. The clone can then replace the water that it transpires.

Keep the light intensity low in the first days, at approximately 60–100 PPFD (the intensity of the light at the plant). Increase the intensity to 150–200 PPFD at the time of hardening off[3]. Measure the intensity with the dome in position, because the plastic decreases the light intensity at the cutting below it.

Dome humidity in each root phaseHumidity is highest at the start. It decreases in steps when roots supply the water.Initial heal (d1–4)Early root (d5–7)Mid root (d8–10)Harden (d11–14)60% RH80% RH100% RH
Figure 5. The target humidity in the dome decreases in stages during the cycle. The clone makes roots and then starts to get water with its roots.[3]
The table gives the environment targets for the four phases. In all phases, the air temperature is 24–26 °C (75–79 °F) and the cube temperature is 22–24 °C (72–75 °F). VPD shows how much the air pulls water from the surface of a leaf. A higher VPD value shows drier air.[3]
PhaseDaysRHVPD (kPa)Light (PPFD)
Initial healing1–485–95%0.3–0.560–100
Start of root growth5–780–85%0.5–0.780–120
Middle of root growth8–1070–80%0.6–0.8100–150
Hardening off11–1465–75%0.8–1.0150–200
Air movement: do not point a fan at the cuttings

A low airflow in the room is good. Do not point a fan directly at clones that have no roots. These clones cannot replace the water that they transpire. Air that flows directly on the clones dries them and quickly causes wilt.

06 · Do this

14-day cloning procedure

A large part of the work in cloning is to know when you must not touch the tray.

The 14-day arc1d1–4do not touch thedome→2d5–7first water andopen vents→3d7examine forwhite roots→4d8–10prop vents wider→5d11hardening-offtest→6d14transplant
Figure 6. At the start, the dome is closed and you do not touch the tray. Then you open the dome in stages when you see roots. The clone starts to get water with its roots.

Days 1–4: Keep the vents fully closed. Do not touch the tray. The humidity in the dome makes the cutting close its leaf pores. Then the cutting uses its energy to make roots.

Days 5–7: It is usually necessary to apply water for the first time. Use the weight of the tray to find the time. Apply water when the weight of the tray is 40–50% less than its weight on Day 0. Do not apply water when the weight loss is less than 30%. Rot starts in a cube that is permanently wet[8]. The color of the cube changes from dark brown to light brown, and this change is the same signal.

Start the clone feed at a low EC, approximately 0.6–1.2 mS/cm (the value is different for each product). Increase the EC only after you see roots. An EC of approximately 1.5 mS/cm can cause damage to soft cuttings. Keep the pH of the feed at 5.5–6.0 and the temperature of the water at 20–22°C (68–72°F).

From day 7, do one burp each day. Start to hold the vents open. Lift one cube at the edge of the tray and examine the cube for white roots.

On day 11, do the test for hardening off. Lift the dome from each tray and wait 10 minutes. If less than 5 clones in a tray show wilt, keep the dome off. If 5 or more clones in a tray show wilt, put the dome on the tray again. Do the test again on the next day. Transplant the clones at approximately day 14.

Vent opening in the cycleYou open the dome in stages, from fully closed to off, when the roots become longer.ClosedBurp 5–10 min/day25–50% open50–100% open1day7.5day14day
Figure 7. The figure shows the opening of the dome vents on each day. At the start, closed vents keep the humidity high for cuttings that have no roots. At the end, fully open vents adapt the cuttings to the air of the room.
The table is a short list of the tasks for each day. The conditions for transplant at the end are the primary check for the decision to transplant the clones.
DayTaskItems to examine
1–4Keep the dome closed. Do not touch the tray.The cuttings have turgor and show no wilt.
5–7Use the tray weight to find the time for the first water. Start to open the vents.The color of the cube changes from dark brown to light brown. The weight loss of the tray is 40–50%.
7+Do one burp each day. Lift one cube at the edge of the tray.The first white roots show.
11Do the test for hardening off. Keep the dome off for 10 minutes.If less than 5 clones in a tray show wilt, keep the dome off.
14Transplant the keepersThe roots are a minimum of 2–3 cm (0.8–1.2 in) long on more than one side of the cube. The cube stays in one piece.
07 · When there is a problem

Troubleshooting

Most problems with clones have a small number of causes. Each cause shows different symptoms, thus you can find the cause quickly.

Find the cause from the symptom, then do the task. Many causes have the same symptoms. Thus correct the cause that is most possible first, and monitor the cuttings for one day.
SymptomPossible causeTask
Much wilt in days 1–2The RH in the dome is too low, the light intensity is too high, or the heat mat is off.Make sure that the RH is a minimum of 85%. Decrease the PPFD. Adjust the cube temperature to 22–24 °C (72–75 °F).
Mold or slime on the cubesWater stays in the tray, the hygiene is bad, or the cubes are too warm.Remove the water that stays in the tray. Touch the cubes only with gloves. Keep the cubes at less than 26 °C (79 °F).
Leaf tips that are dry and brownThe feed EC or the VPD is too high (the air is too dry).Decrease the EC by 0.2–0.3. Increase the RH. Open the vents more slowly.
Yellow leaves before the roots showThe mother plant had a nutrient deficiency, or the feed EC is too low.Examine the nutrition of the mother plant. In the next cycle, increase the EC by a small quantity.
White mold with fibers in the domeThe humidity is too high and there is no air exchange.Do more burps. Always do the hygiene procedures for the dome.
Irregular rootingThe moisture of the cubes or the quantity of hormone is different between cubes.Soak all the cubes equally. Put each cutting in the gel to the same depth.
Tools and hands move disease

Sterilize the tools in 71% isopropyl alcohol for a minimum of 2 minutes (or in chlorine dioxide for a minimum of 180 seconds). Touch the cubes only with gloves. In a propagation room, tools and hands move disease from one cutting to the next. Hands without gloves move algae and pathogens[7]. Good hygiene prevents the organisms of damping-off disease and root rot. These organisms kill all the cuttings in a tray[7].

08 · Typical results

Expected results and limitations

A first target of 90 percent rooting is possible. Operators who do cloning frequently get 95 percent or more[1]. The roots show in 10 to 14 days. If a cutting has no roots after 21 days, there is a problem. Do an investigation of the cause. Do not wait for the cutting.

Some cuttings do not give a satisfactory result. At transplant, you select the cuttings to keep and the cuttings to discard. This culling is part of the procedure.

A keeper has strong roots and light green tops. A reject has only one to three weak roots. A kill has no roots, and you discard it.

Make 15 to 40 percent more cuttings than the necessary number of plants. Thus the number of plants is sufficient after you discard the weak cuttings.

A target of 100 plants with 40% more cuttingsMake more cuttings than necessary. The batch is full after culling at each stage.04080120160140 plantsCuttings taken120 plantsVeg (rooted)100 plantsFlowered
Figure 8. The figure starts with the number of plants for the flowering stage. Make more cuttings at the start. Thus you have the target number of plants after the culling at the rooting stage and at the vegetative stage.
Culling at transplant: keepers, rejects, killsIn an adjusted room, approximately nine of ten are strong keepers025507510090%Keepers6%Rejects4%Kills
Figure 9. The figure shows a good tray after the culling. Most cuttings are strong keepers. A small number of cuttings are weak rejects, and a small number are kills.[1]

Some cultivars make roots more slowly. For these cultivars, make the cuttings some days before the usual date. Thus you can transplant the cuttings at the correct date. Record the tray weights, the EC and pH, and the rooting rate for each batch. Then, in the next cycle, you know the cultivars that you must cut before the usual date. You also know if there is a drift in the room conditions.

Three important items
  1. 90% is the minimum, not the maximum. A new grower who gets 90% has a good result, and an adjusted room gets 95% or more. If the rate is less than 80%, the environment or the hygiene is incorrect.
  2. Discard all the weak clones at transplant. When you discard the weak clones at the start, the batch keeps its uniformity.
  3. The environment has the largest effect. The humidity, the cube temperature and the light have more effect than the hormone product that you use. Adjust these items first.

After the clones have roots and you complete the hardening off, the next task is to move the clones into stronger light. Do not cause stress to the clones. Refer to the light acclimation guide. Use the IPM hygiene procedure to keep the propagation room clean from the first day.

Related papers
Light acclimation
Increase light in steps and prevent damage to leaves
IPM SOP
Examine the crop, make a decision, apply a treatment
Tissue culture
Clean genetics from a small piece of tissue

References

  1. 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. https://doi.org/10.1139/cjps-2018-0038
  2. Esposito, L.G.A., et al. (2026). Analysis of Marijuana (Cannabis sativa L.) Cuttings: Morphological and Colorimetric Traits as Predictors for Optimization of Vegetative Reproduction. Plants, 15(3), 440. https://doi.org/10.3390/plants15030440
  3. Kim, B., Hahm, S., Lee, Y.J., Bok, G., & Park, J. (2025). Light, Temperature, and Relative Humidity Influence the Adventitious Rooting of Cannabis Stem Cuttings. Horticultural Science and Technology, 43(4), 480-493. https://doi.org/10.7235/HORT.20250043
  4. Landis, H., et al. (2022). Impact of Indole-3-butyric Acid Concentration and Formulation and Propagation Environment on Rooting Success of 'I3' Hemp by Stem Cuttings. HortTechnology, 32(3), 321-330. https://doi.org/10.21273/HORTTECH05016-21
  5. Fattorini, L., Veloccia, A., Della Rovere, F., D'Angeli, S., Falasca, G., & Altamura, M.M. (2017). Indole-3-butyric acid promotes adventitious rooting in Arabidopsis thaliana thin cell layers by conversion into indole-3-acetic acid and stimulation of anthranilate synthase activity. BMC Plant Biology, 17, 121. https://doi.org/10.1186/s12870-017-1071-x
  6. Lopez, R.G., & Runkle, E.S. (2008). Photosynthetic daily light integral during propagation influences rooting and growth of cuttings and subsequent development. HortScience, 43(7), 2052-2059. https://doi.org/10.21273/HORTSCI.43.7.2052
  7. Punja, Z.K., Tirajoh, A., Collyer, D., & Ni, L. (2023). Biological control of Fusarium oxysporum causing damping-off and Pythium myriotylum causing root and crown rot on cannabis (Cannabis sativa L.) plants. Canadian Journal of Plant Pathology, 45(3), 245-264. https://doi.org/10.1080/07060661.2023.2172082
  8. Lopez, R.G. & Currey, C.J. (Michigan State University Extension). Moisture management during vegetative cutting propagation. MSU Extension / Greenhouse floriculture. (source not from a journal, for example from a manufacturer) https://www.canr.msu.edu/news/moisture_management_during_vegetative_cutting_propagation
  9. Liu, Y., et al. (2023). Photosynthetic Acclimation of Shade-Grown Soybean Seedlings to a High-Light Environment. Plants/Frontiers in Plant Science (shade-to-high-light photoinhibition study). https://pmc.ncbi.nlm.nih.gov/articles/PMC10305168/

Each citation in the paper, for example [1], refers to an item in this list. Each item is a primary source or an instruction from an authority, unless the item shows a different type. The results of cannabis tissue culture change much with the genotype. Before you use the dilutions, hormone doses and local regulations, make sure that they agree with the primary sources.