How To Clone Hemp & Cannabis Plants

This guide provides a detailed protocol for cutting hemp or cannabis clones from a mother or donor plant, and optimizing the rooting process using best practices in a controlled grow room environment. Following this procedure ensures high clone survival rates, rapid root development, and uniform plant health.

This procedure applies to anyone involved in nursery propagation and covers the steps from selecting healthy mother plants to preparing vigorous clones for transplant.

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Procedure

Selecting & Preparing the Mother Plant:

1. Choose a Healthy Mother Plant:

• Select a vigorous, pest/disease-free plant that has been in the vegetative stage for at least 4–6 weeks. Preferred that this donor plant has been screened for pathogens like HLV hop latent viroid, fusarium, or pythium to ensure best practices when propagating future plants.

(Use test kits from 3 Rivers Biotech our partnered / preferred lab)

• Avoid taking cuttings from flowering plants, as clones from them may struggle to revert to vegetative growth. It can be done, with lots of time, but could super stress the plant and not provide as vigorous cuttings after reverting to vegetative stage.

2. Pre-Cloning Preparation (24–48 Hours Before Cutting):

• Water the mother plant with a normal nutrient solution to ensure it is hydrated.

• Avoid heavy nitrogen feeding before taking clones, as excess nitrogen can slow root development.

• Perform a light defoliation to increase airflow and make cutting easier.

3. Sterilization & Setup:

• Sanitize all tools, including scalpels, razors, and work surfaces, using 20% Bleach solution OR 2% Virkon-S 

• Pour Clonex Gel into Shot Glass (Only pour amount you will need) Reseal container and store in cool dry place. Do not pour unused Clonex Gel from the shot glass back into the container.

• Wear disposable gloves to prevent contamination.

Choose a Medium:

• Rockwool cubes: Pre-soak in pH 5.5-5.8 R.O. water with Clonex Clone Solution before inserting clones. (Recommended dilution ratio is 5ml of Clonex Clone Solution Per Pint (500ml) of RO water or 10ml per Quart (1000ml) of RO water.) Discard all the runoff left behind. Plugs and cubes should not sit in nutrient solution. 

• Peat plugs or rapid rooters: Moisten with Clonex Clone Solution slightly before use. (Recommended dilution ratio is 5ml of Clonex Clone Solution Per Pint (500ml) of RO water or 10ml per Quart (1000ml) of RO water.) Discard all the runoff left behind. Plugs and cubes should not sit in nutrient solution. 

• Place cubes or plugs into the clone tray cells for as many or slightly more clones than you think you will be making.

4. Cutting Clones

Identify Healthy Mother Plant & Suitable Branches For Cuttings:

• Select 6”-8” -long branches with at least 2-3 nodes.

• Look for firm, healthy growth with no signs of stress or nutrient deficiency.

Make the Cut:

• Use a sterilized shear, razor blade, or scalpel to cut at a 45-degree angle just below a node.

(Pro Tip: Soak shears in 20% bleach solution for 30 secs, and rotate shears between mother plants to mitigate disease spread)

Remove Excess Leaves:

• Trim off lower leaves on cuttings to prevent energy waste and overcrowding in tray

• Cut large fan leaves in half to reduce transpiration. (Optional but preferred with 50-72ct cell trays due to crowding) 

• Place fresh cuttings in a cup of RO water until they are ready to be dipped into Clonex rooting gel and plugged. This keeps air from entering the stem and causing an embolism which will lower your success rates of rooting. 

5. Apply Rooting Hormone:

• Dip the freshly cut shoot tip end into Clonex Gel or other rooting hormone (gel, powder, or liquid).

• Ensure an even coating but avoid excessive application. (Dip only 1” of bottom stem) 

• Gently hold the stem downwards when placing the cutting in the Rooting Medium (cubes or plugs)

6. Insert the Cuttings:

• Gently place the cut end of the cutting into the medium, ensuring good contact.

• Do not push too deep—around 1–1.5 inches is ideal.

• Once Tray is full, lightly mist the Cuttings with Clonex Mist. Avoid over spraying, which

makes the leaves droop. If using a Dome, lightly mist inside of Dome with RO Water and cover the tray with the dome vents closed. 

• Repeat misting Clones with Clonex Mist every 2 Days starting 2 Days after first application.

Stop using Clonex Mist once Clones get transplanted.

7. Humidity Control:

• Place cuttings plugged in media in a propagation tray, under a humidity dome to maintain high humidity (80–90%).

• Mist clones lightly as mentioned above, but do not over-saturate the leaves.

8. Rooting Conditions & Daily Care

Environmental Conditions:

• Temperature: 75–78°F (Pro Tip: Use Heated Seedling Mat underneath tray, as the root zone can be slightly warmer to encourage roots to strike. Use the heat mat only for the first few days then turn off).

• Humidity: 80–90% for the first 3–5 days, gradually reducing to 70% over time.

• Light: Low-intensity LED or fluorescent (18/6 light cycle). – Approx 100-200 PAR

• Airflow: Ensure gentle air circulation in common grow space to prevent mold while maintaining humidity.

9. Daily Maintenance:

• Check for wilting or yellowing and remove unhealthy / dampened off clones. 

• Lightly mist clones as needed but avoid waterlogging.

• After Day 3-5, begin to open the humidity dome ¼ turn each day to harden off clones gradually.

• Monitor the temp & RH% inside the dome and vent “burp” the tray as needed to maintain. 

• Remove dome entirely usually by day 7-10 depending on strain and environment. 

• For the first 7 Days after cutting Clones when needed, prepare RO Water, balanced with ½

strength Cal/Mag. Add Clonex Clone Solution until you reach 0.4 – 0.5 EC Adjust pH to 5.8 – 6.0

• After 7 Days or when the roots emerge out of the bottom of the cubes / plugs do the following when watering plugs; Add ¾ strength Cal/Mag to RO Water and then add Clonex Clone Solution until you reach 0.8 – 1.0 EC* and pH should be adjusted to 5.8 – 6.0. * Some Cultivars will require higher EC values.

• Some growers opt to use a vegetative phase fertilizer at the same EC as their mother plants when rooting their clones as we have done too with great success. You just need to monitor for over feeding. Try a couple methods to see what works best for you and your cultivars.

10. Root Development Timeline:

• Day 3–5: First signs of callus formation.

• Day 7–10: Small root structures visible in most clones. Dome removed.

• Day 10–14: Strong root growth; clones are ready for transplant.

11. Hardening Off & Transplanting Clones

Acclimation Before Transplanting:

• Gradually expose clones to lower humidity by venting the dome for longer periods each day.

• Increase light intensity slowly to prepare them for the main growroom. (Use PAR Meter)

12. Transplanting Clones:

• Once roots are well-developed, transplant into rockwool cubes, soil, coco, or other hydroponic systems. Be sure to match the pH & EC along with room parameters to best acclimate.

• Water immediately with a nutrient solution similar parameters as the mother plants were fed at typically (EC 2.0 – 2.5) 

13. Quality Control & Record Keeping

• Track Success Rates: Log the number of clones taken vs. successfully rooted clones.

• Monitor Environmental Conditions: Record temperature, humidity, and light levels daily.

• Identify Improvements: Adjust cloning methods based on success rates and clone health.

Be sure to check out our other blog on How to Acclimate and Transplant Clones CLICK HERE 

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