Cloning a cannabis plant means taking a cutting it and propagating it so that it develops a root system and grows into a separate plant with identical genetics to the mother plant. It’s a method of asexual propagation. Multiple plants for little to no cost – what’s not to like? In this article, we are going to share the best ways of cloning a weed plant and also look at the advantages and disadvantages of cloning versus growing from seed. Here’s our step by step guide:
How to clone a weed plant?
- Choose a mother plant
- Cut the branches
- Develop roots
- Grow in a tent or mini greenhouse
- Use high-quality water
Look for your healthiest weed plant during the vegetative phase. It needs to be at least eight weeks old, or it won’t be mature enough to develop roots. It needs to have a substantial root system, be growing rapidly, and be free from any disease or pests.
We recommend taking cuttings from female plants. Autoflowers are virtually impossible to clone and not worth the effort. Sativas are the easiest strains to clone; Indicas require a bit more effort.
Take note – it is never advisable to take cuttings from cloned weed plants – this could result in mutations, ‘genetic drift’ and all sorts of bad things.
Once you have selected the mother plant, give it 10 percent less nitrogen for at least a week before taking the cutting.
Wash your hands – good hygiene is essential for successful cloning.
Use a pair of clean and sharp secateurs or – even better – a disposable scalpel – to snip the clone from the mother plant. Use alcohol to sterilise all utensils and get everything ready and organised before you get started as cuttings will wilt very quickly.
Take cuttings from the base of the plant, as they aren’t as essential as the top branches from a production point of view. Try and visualise where the roots will grow. Ensure there are a couple of nodes above the top of the cutting so that it is long enough. Choose a branch which is sufficiently large as to have at least six inches remaining and with a remaining pair of leaves so that it can regrow.
Cut the branch at a 45-degree angle – in the same way as you would prepare cut flowers before placing them in a glass of water. The principle is the same – to encourage as much water absorption as possible.
Take the cutting and keep it out of direct sunlight and the open air to encourage rooting – although it will also cause etiolation. Wrap the end of the cutting with gardening tape to protect it from the open air.
Take as many cuttings as you can – and more than you think you will need. Although genetically identical, cloned cannabis plants will not all grow the same way and some will develop into healthier specimens than others.
There are several things you can do to help the fresh cuttings develop roots. One is to apply commercial rooting hormone powder or gel. These contain auxins which help the roots to grow. It is important that the package is sealed and unbroken as the contents must be sterile. Apply the product according to the directions and store in a cool, dark place until you are ready to pot up.
Trim fan leaves in half to reduce transpiration so the newly developed roots don’t have as much work to do.
Remove any seal from the cutting and carefully place in a rooting cube which can be bought cheaply at any garden centre. You can use a peat potting compost, Rockwool or coconut coir. If you are using Rockwool, you will first need to soak it overnight in a pH balanced (5.5 – 6.5) solution. You might prefer to use a soilless mixture which comes in a gel or liquid form if you are planning to use a hydroponic system where the cuttings grow in water with added nutrients.
Newly planted clones need high levels of humidity and gentle fluorescent lighting to thrive and develop into plants capable of producing dank buds. You could use HPS lamps, but cuttings tend to find fluorescent lights to be more beneficial and less stressful. Handle the plants as delicately as possible and ensure that there are enough ventilation slots to allow air to circulate and encourage transpiration.
The temperature should be a constant 24 to 28 degrees Celsius. You could use a heating mat if you are worried that the temperature is too low.
To maximise the chances of success, plain old tap water isn’t really suitable. Use filtered chlorine-free water which is low in minerals.
Once your clones are safely in their growing medium, all you need to do is carefully monitor them until they develop roots. This involves checking them at least once a day, spraying the leaves with filtered water and raising the lid of the grow tent to allow fresh air in. This is essential to reduce the risk of mould spores which could easily destroy the young clones. Roots should develop between one and three weeks.
How can I tell that roots have grown?
The stem will start to grow. If the tips of the leaves turn yellow, it is a sign that there is strong root development. You may also see roots emerging from the base of the grow cube.
Help my clones are wilting! What should I do?
It is normal for the leaves of clones to wilt for the first day after they have been taken. They should quickly revive. If they don’t recover within a day or so, you should discard them. This is why you should always take more cuttings than you think you will need.
Cloning plants or growing from seed – which is best?
Many growers ask us, whether growing weed from seeds or clones are best and there is no easy answer as both have advantages and disadvantages. Let’s look at the pros and cons of both:
Clones – Pros
- If you have a favourite strain whose genetics you love, you can replicate it by cloning it;
- Cloning is very fast, once the plants take root as you don’t have to wait for seeds to germinate;
- Cloning is very cheap;
- As long as you know the gender of the parent plant, you can guarantee the gender of the clones, thus reducing wastage and time.
Clones – Cons
- You still need to have access to a mother plant;
- If the mother plant has any disease or infirmities, these will be replicated;
- You need to have a certain amount of horticultural expertise;
- Clones frequently don’t grow very tall and may produce inferior yields;
- Clones are faster but arguably require more nurturing and tending in their early stages;
- Cloning autoflowers isn’t worth it, so you will need to adjust the hours of daylight to switch to the flowering phase at the appropriate point.