How to clone cannabis plants

What is a cannabis clone?

A clone is a cutting, such as a branch, that is cut off of a living marijuana plant, which will then grow into a plant itself. A clone has the same genetic makeup as the plant it was taken from, which is called the mother plant.

A typical clone is about 6 inches in length, give or take, and after cutting it off the mother plant, the clone is put into a medium such as a root cube and given a hormone to encourage root growth.

After roots develop, it is then transplanted into a pot or the ground, and it will grow like any weed plant.  

Why clone cannabis plants?

If you don’t want to mess with seeds, clones can be a great option for starting a marijuana plant. Growing weed from a clone will save you time—even though they need time to root out, you don’t have to germinate seeds, which will shave off a month or so of the growing process. 

Clones will also save space in your garden—with seeds, you have to grow many and sex them out to identify and get rid of the males. Also, usually some seeds don’t germinate. You’ll need extra space for all those seeds, and they might not even turn into full plants. 

If you take a clone from a plant you already have, they’re free! You just need to invest in some supplies. Although, you can buy clones from a dispensary if you want. 

One of the best things about clones is they are exact genetic replicas of the mother plant from which they were taken. If you have a particular marijuana plant you like, whether for its appearance, smell, effects, or something else, you can take clones of it and grow it again, ad infinitum. 

There is some speculation that clones can degrade over time based on environment stressors and other factors, but that is open to debate.

What is a cannabis mother plant?

A mother plant is any cannabis plant you take a clone from. Mothers should be healthy and sturdy, as their genetics will pass on to the clones—if you have a sickly mother plant, its clones will also be sickly.   

Mother plants always stay in the vegetative stage as clones are clipped off. It’s important to not take cuttings off a flowering weed plant—this can cause the clone to turn into a hermaphrodite and may also damage the flowering plant. 

Some growers have dedicated mother plants only for taking cuttings, but this setup takes up a lot of space and materials—you’ll need to keep the mother plant alive, but you won’t get any buds off it because it’ll always stay in the vegetative stage. Some growers find it hard to justify devoting time, energy, and space to plants that won’t produce buds. If your grow space is tight, this might not be the best setup.

Another method growers employ is to take cuttings off a set of mother plants before they flower, then flip the mothers into the flowering stage. The next generation of clones is grown, and when those get big enough, cuttings will be taken from those before getting flipped into flower. Because clones are genetically identical, each generation will be an exact copy of the first-generation mother and all subsequent mothers.

Cannabis mother plants guarantee genetic consistency, so each new generation of clones taken will have the same taste, flavor, effects, and other characteristics. Clones will also generally grow at the same rate as the mother, produce a similar quality product, and grow with the same vigor, allowing you to dial in your process and really get to know how to grow that particular weed plant. 

Clones also guarantee that all of your weed plants are females, so you don’t have to spend time growing from seed, sexing plants, and discarding males. 

What to look for in a mother plant

As genetics are identical between a mother and a clone, it’s important to choose a good plant as a mother. A wilty plant, or one that doesn’t produce good buds, won’t make a good mother.

Growers usually look for these qualities in a mother plant:

• Sturdy, vibrant growth
• Great aromas and flavors
• Big yields
• Dense trichomes
• Resistent to pests and mold

How to clone a cannabis plant

What do you need to clone cannabis?

Cloning cannabis is relatively easy and requires just a few key items:

• Scissors (for taking cuttings off the mother plant)
• Razor (for trimming up cuttings)
• Rooting setup (tray/tray-cell insert/dome/root cubes/heat mat, or an auto-cloner)
• Rooting hormone

Choose a rooting medium and setup

Common rooting mediums include rooting cubes, rockwool, or other non-soil equivalents 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 of any kind, you’ll need to invest in a tray, a tray-cell insert, and a dome. The clones will go in the cubes, the cubes into the tray-cells, and all of 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. There is an initial cost for buying an auto-cloner, but if you plan on cloning a lot, they are worth it. Auto-cloners cut down on the amount of labor needed to care for clones. Using aeroponics, these machines spray the bottoms of your cuttings with nutrient water at set intervals to promote root growth. 

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.

For more info on cloning setups, check out our Guide to cannabis cloning equipment.

How to take a cutting from a cannabis plant

When selecting a mother plant to clone from, look for plants that are healthy, sturdy, and at least two months into the vegetative cycle. Don’t take a clone off a plant once it starts flowering.

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.

Be sure to work in a sterile environment. Use gloves and disinfect razors and scissors.

To take a cutting: 

• 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 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, put a collar around it and place it in the auto-cloner; you’ll put rooting hormone in the cloner after all cuttings have been taken.
• Once done taking the 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.

Transplanting your weed 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 root out quicker, and some longer. You’ll know they’re ready when the white roots are an inch or two in length.

When getting ready to transplant, be sure to keep the environment sterile. Transplant shock can occur, so be sure to use gloves when handling clones.

To transplant:

• Put soil in your pots first.
• Water the soil before transplanting so soil doesn’t move around once the clone is in its new home.
• Once the water has drained, dig out a hole 1-2 inches deep with two fingers, or just enough to bury all the roots.
• Put the clone in and gently cover with soil.

What to look for when buying a marijuana clone

If you live in a medical or adult-use state, you’ll be able to get clones from some local weed shops, but make sure it’s a reputable shop.

Most of the time, these clones come from growers who focus solely on producing clones, but sometimes cuttings will come from a third-party source. When purchasing clones for your home garden, always ask your shop where they came from. If you can’t get a legitimate answer, find another source.

It’s important to know the origin of your clones because that’s where problems originate—diseases, pests, incorrectly labeled genetics, and unknown pesticide residues can come with a mystery clone.

Never hesitate to research a dispensary or grow facility before buying clones.

Inspect the cannabis clones

Not all pests, diseases, pesticide residues, or genetic markers will be easy to spot with the naked eye, but give your clones a good look before introducing them to your garden. If they look sickly or weak, they likely won’t grow well.

Stem width

A clone’s stem width is a great way to get a sense of its overall health and vigor. Thin and narrow stems typically mean the clone was taken from a weak or less viable branch. These cuttings may be more prone to disease or death and their root systems may take longer to develop.

Pests

Be sure to inspect all areas of your clone for the presence of pests. Large pests such as fungus gnats and spider mites can be spotted relatively easily.

Check under each leaf and also check the soil medium, as some pests live there. Certain pests can also leave markers—spider mites leave spots and webbing, and other insects can leave trace bite marks.

Disease

Many diseases can be difficult to detect in cuttings, but there are a few visual cues that can be seen early on. A lack of vigor is a major cue—check for limping leaves, irregular or mutated growth, and discoloration.

Powdery mildew (PM) is a very common disease found on clones, and mold spores can transfer to other plants. Keep an eye out for white powder on stems and leaves.

It’s almost impossible to detect harmful pesticides or fungicides on a clone. Often, these applications leave zero residue and can stay on a plant for the rest of the plant’s life. If you see any suspicious residue on a clone, ask the grower about their in-house integrated pest management (IPM) and always err on the side of caution.

Clean and quarantine your cannabis clones

If some clones look OK at the shop and you decide to take them home, make sure to take a few last precautionary steps before introducing them to the rest of your garden.

First, transplant your new weed clones into a more permanent container and medium. Often the grow medium used to house fresh cuttings at the shop will be different than what you use. Also, pests may be present in its medium when you bought it—transplanting your clone to a cleaner space will help mitigate any potential root damage.

Take this time to properly clean your clone with whatever IPM solution you deem fit. A popular method for cleaning new clones involves dipping them into a light solution of whatever safe and approved pesticide you choose.

After your clones have been properly cleaned and transplanted into their new medium, make sure to keep them quarantined for a few days to a week. Doing this will protect the rest of your garden if they do develop problems, and you’ll be able to pull them out easily.

If they look good after a week or so, go ahead and introduce them to the rest of your garden.

Patrick Bennett and Trevor Hennings contributed to this article.