How to clone cannabis plants
Cloning cannabis is relatively easy and requires just a few key items:
- Scissors (for cutting branches off the mother plant)
- Razor (for trimming up cuttings)
- Rooting setup (tray/dome/root cubes, or an auto-cloner)
- Rooting hormone
Choose a rooting medium and setup
Common rooting mediums include rockwool, rooting cubes, or another non-soil equivalent like peat or foam. Rockwool is melted rock that has been spun into a fine thread, and it has terrific airflow and moisture retention. You can find any of these cubes at most grow stores or online.
If you’re using cubes, you’ll need to invest in a tray, a tray-cell insert, and a dome. The clones will go in the cubes, the cubes in the tray-cells, and that sits in a tray which will hold water. To keep in humidity make sure to use a dome over your tray, and you may even want to use a heat mat.
Another method is to use an auto-cloner. These cut down on the amount of labor needed to feed and care for clones. Using aeroponics, these machines spray the bottoms of your cuttings with nutrient water at set intervals to promote root growth. They are more expensive than the traditional tray/dome/root cube setup, but they are becoming more and more popular.
Experiment to see which setup works best for you. Whichever method you choose, make sure your new clones get plenty of light—preferably 18 hours—and humidity.
How to take a cutting
When selecting a mother plant to clone, look for plants that are healthy, sturdy, and at least two months into the vegetative cycle. You shouldn’t take a clone off a plant once it starts flowering.
Here’s how to take a cutting:
- Don’t fertilize mother plants for a few days leading up to taking cuttings. This will allow nitrogen to work its way out of the leaves. When you take cuttings, an excess of nitrogen in the leaves and stems will trick your clones into attempting to grow vegetation instead of diverting energy to rooting.
- Work in a sterile environment. Use gloves and disinfect razors and scissors.
- Look for branches that are sturdy and healthy. You want at least two nodes on the final cutting, so pick a branch that is healthy and long enough. A sturdy clone will lead to a sturdy plant.
- Cut the clone off of the mother, cutting above the node on the mother plant. It’s OK to use scissors here; it may be hard to get a razor in the middle of the mother plant.
- Then, using a razor, cut below the bottom node on the fresh cutting at a 45° angle to the branch. This will increase the surface area of the rooting surface, promoting faster growth.
- Place your fresh cutting immediately into a rooting hormone. Then, put it directly into a root cube. If using an auto-cloner, you’ll put rooting hormone in the cloner after you take all your cuttings.
- Once done taking a cutting, remove unnecessary leaves toward the bottom and clip off the tips of the remaining fan leaves on the cutting. This supports photosynthesis, helping your clones uptake nutrients and water.
Transplant your clones
Check your clones daily to make sure they have enough water by checking the bottom of the tray or auto-cloner. To increase humidity, you can spray water on the leaves with a spray bottle. If any clones die, discard them so they don’t cause mold in the rest of the clones and also to give the remaining clones more space.
Most clones will be ready to transplant into soil in 10-14 days, but some may take longer. You’ll know they’re ready when the white roots are an inch or two in length.
To transplant:
- Put soil in your pots first.
- Water the soil before you put in the clone, so soil doesn’t move around once the clone is in its new home.
- Once the water has drained, with two fingers, dig out a hole 1-2 inches deep, or just enough to bury all the roots.
- Put the clone in and gently cover with soil.
Cloning can do wonders for your cannabis garden by saving you time and money, and ensuring a genetically consistent crop. You don’t need much to get started, and if done correctly, you can have a perpetual harvest of your favorite strains year-round.