Cannabis, like many other plants, can be propagated through sexual and asexual reproduction. Sexual reproduction involves male and female flower parts, and separate male and female plants in the case of cannabis, followed by fertilization and seed production. Asexual reproduction is also known as cloning.

Many plants naturally clone themselves by sprouting roots on the underside of soil-touching leaves and branches and spreading systems of underground rhizomes and tendrils, relocating the genetically identical plant in new locations. Cannabis is capable of this also, and it most commonly clones with human assistance. There are good reasons for cloning your cannabis plants.

Reasons for Cloning Cannabis Plants

If you do not take clones of your plants and you keep on growing cannabis year after year, you have to acquire viable seeds or seedlings of the variety you want to grow every season. Getting seeds or seedlings usually involves expense as well as time and effort to locate the varieties you want. Cloning your cannabis plants means you have new plants every season for free.

Cloning your own cannabis also gives you maximum control over the variety you are growing because each time you clone you get new plants with the same genetics as the parent plant. Businesses selling cannabis seeds and seedlings do not always have the same varieties each year, and a type you like may be unavailable or hard to find.  If you have a favorite variety, cloning your cannabis plants assures you of having what you want.

When you clone your cannabis plants, you can also maximize your yield and improve plant health. Some individual plants grow faster and stronger and have a better yield. When you clone, you select and maintain these genetics from one season to the next.

4 Steps for Cloning Cannabis Plants

Cloning cannabis at home is simple and straightforward. The tools you need are:

  • A sharp razor or razor knife
  • Clean, cool water
  • A rooting medium of rock wool, soil mix, or water in a clean glass container
  • Mild nutrient solution or powder for rooting medium
  • A bottle of rooting hormone (optional)

Step 1: Selecting and preparing a plant for cloning

The parent plant should be healthy and at least three weeks and up to two months into the vegetative growth cycle to maximize root growth in the cutting.  Do not give the plant any nitrogen fertilizer for several days before taking the cutting to avoid vegetative growth in favor of root development in the clone.

Step 2: Taking the cutting

Use a sterile, sharp razor blade or a razor knife to cut the clone from the mother plant. Scissors tend to crush the stem, and it is better to avoid them for this cut. Choose a healthy leaf or small branch near the bottom of the plant, and cut the stem at a 45-degree angle near the base where it attaches to the main stem of the plant.

Use a sharp pair of scissors to cut fan leaves in half and to trim-off any small or damaged leaves.  Cut off leaves on the bottom third of the stem where it goes into the rooting medium. Remove leaves which touch the surface of the rooting medium once you set the clone in the medium. Making several lateral cuts across the base of the stem before placing it into the rooting medium can help spur root development.

Step 3: Rooting the cutting

Immediately transfer newly cut clones into clean, fresh water. After that, you can dip the stem into a rooting hormone following the directions on the package. Then use one of three possible rooting mediums to establish the clone until it develops roots and new vegetative growth in a week to three weeks.

Planting Mediums

Rock wool medium for clones: These are easy to find and inexpensive. Select a cube size with a planting hole approximately the same diameter as the stem of your cuttings.

Prepare the rock wool before you plant the clone by soaking the cubes for about an hour in 5.5 pH level adjusted water. Follow this by soaking the cubes in a mild nutrient solution. Read and follow the instructions on pH adjustment solutions, fertilizers, and rooting hormones before using them.

Shake out the excess solution from the cubes after soaking but do not squeeze them, or you can damage their air and moisture holding capacity. Plant one clone per cube and set the cubes in planting trays.

Cloning in a soil medium: Use a seed starting or transplant mix or make one using peat moss, vermiculite, perlite, and a small amount of loamy garden soil or well-finished compost. Do not over-fertilize the rooting medium or the clones will grow leaves instead of developing strong roots.  Plant the bottom 1 to 2 inches (2.5 to 5cm) of the stem into the moist soil mix in small containers with good drainage.

Starting Clones in Water: Use fresh, cold water and put it in a clean glass container. Use a container size matched to the size of the clone. Half-pint jars work well for smaller clones. Use a larger jar or glass if the clone is bigger. Fill the jar to within about an inch (2.5cm) of the top and set the clone into the water, so the bottom third is immersed.

Keep the rock wool cubes, soil, or water rooting medium in a moderately humid location and a temperature of approximately 75ºF (23.8C).  Check the moisture daily or more often in rock wool cubes and soil, and replenish water in glass containers as it evaporates. You can place a clear, plastic bag lightly over the clones to help keep humidity up. Give the clones plenty of light, up to 18 hours a day, for best results.

Step 4: Transplanting the clones

Watch the clones closely and look for root development and new vegetative growth. In water, new roots are easy to see. Check the sides and underneath of rock wool cubes for roots, and you can gently remove a soil-planted clone from its container and look for roots growing around the outer edge of the soil.

As soon as you see healthy root growth, transplant the clone into a larger pot where it can grow to full size or until it is ready for transplanting into the garden.

You can take clones of clones on and on from one year to the next for many years and even decades, saving money, time, and getting a reliable and consistent product every season.