How To Clone Hydroponic Marijuana Plants
Cloning, also called cutting or striking, is taking a section from a mother plant. When a cutting is taken properly and provided with conditions that it can live and grow in, it will develop and mature like a plant grown from seed.
A clone will be an exact genetic copy of the mother plant it was taken from. Clones of marijuana plants are taken and grown to produce a harvest, instead of starting from seed.
A major benefit of clones is that if taken from a mother plant that produces a large potent harvest, the clone will produce a large potent harvest if grown in the same conditions.
When growing a plant from seed there is no way to tell how it will do until it is grown.
Another benefit of clones when compared to regular marijuana seed, is that if you know the sex of the mother plant you will know the sex of the clone, because it will be the same.
A drawback of clones is they don't grow quite as vigorously, when compared with plants that originated from seed. This isn't usually noticeable with hydroponics or growing with soil indoors, but is a concern when plants are grown outdoors in soil.
Once you decide that cloning is right for you, follow the procedure below. After cloning, you can put the clones into any type of hydroponic system or cloner.
100% success rates when cloning are common with most marijuana strains. There are some exceptional marijuana strains that can be more difficult to clone than the majority are.
It will be in your best interest to do an internet search for information about cloning success rates with the strain you have, before attempting to clone.
Step By Step
List Of Materials
Choosing A Mother
Planning The Cuts
Decide on how many clones you need, and before you start the actual cutting, plan how you will cut those clones from the mother plant, or plants, you have available.
Clones that are 5-6 inches/12-15 cm will grow quickest. They can be as short as about 1 inch/2.5 cm, but as the length of the clone decreases the length of time it takes to mature increases.
You will be trimming the ends off cuttings to their final length at the end of the procedure, so the initial rough cut will have to be slightly longer than the final length of the clone.
Clones should be taken from the lowest branches of a mother plant. You can cut off the entire branch that the cutting will be taken from.
If you do cut off the entire branch, you can probably take several clones from it, if the branch is long enough. Sometimes smaller branches that grow from the branch you cut off will be long enough to clone.
Rather than cutting off the entire branch, if you only need 1 or 2 clones, you can just cut the tip from the end of the branches you are taking clones from, leaving the rest of the branch on the plant to continue growing.
Consider that the roots that emerge from new clones will grow from the sides and not the bottom of the stem. Roots grow fastest from areas near the base of the stem where excess leaves were cut off, the area is called a node.
For faster growth rates, when cutting the clone to its final length it is important to have at least one node area near the base of the stem so it comes in contact with the media or nutrient solution. Roots will grow from the sides of the stem if there is no node, but it will take longer
Procedure For Taking Clones
Once you have decided on the plant or plants you want to clone, set up the cloner or hydroponic system that the clones will be put in, and get everything organized.
When everything is together and organized, clean up and sterilize items that will come into contact with the cuttings you take.
Take cuttings from the lowest branches of the mother plant. Cut clones from the branch to a length that is slightly longer than the length you would like the clones to be when finished.
Cut off all excess leaves from the cutting except for leaves growing from the tip and 2-3 of the larger leaves closest to the tip.
After all the excess leaves are trimmed the clone should have no leaves that project more than about 1.5 inches/3.8 cm from the stem.
If necessary, leaves that project more than 1.5 inches/3.8 cm from the stem should be clipped. Perform this procedure until all the clones are done.
You should be able to place a glass with a 4 inch/10 cm diameter over a clone without the glass touching any leaves.
Place the stem of the cuttings you take in a container filled with distilled water, reverse osmosis water, or very mild hydroponic nutrient solution with the pH of the water or nutrient solution to as close to 5.8-6.2 as possible.
Always put cuttings in a container with water or nutrient solution when they are not being worked on. Do not take cuttings out of the water or nutrient solution for more than a few minutes at a time.
When all the clones are ready, the next step is cutting them to length. Clones can be 3 inches/7 cm or even shorter. But they will grow quickest when cut to 5-6 inches/13-15 cm long.
When cutting the clones to length, the cut should be no more than about 1/4 inch (6 mm) below where an excess leaf was cut off the plant, the node.
If necessary, the length of the clone can be a bit longer or shorter, if it means that the nodes where leaves were cut off, will make better contact with the hydroponic media or nutrient solution.
If the clone will be put in hydroponic media, make the final cut on the bottom of the stem at a 45° angle, so it is easier than a blunt end to insert into the media.
If you are going to put the clone in an aeroponic cloner or another type of hydroponic system that does not use hydroponic media, the final cut can be straight, or any other angle you prefer.
You can make the final cut under water/nutrient solution. This is not necessary for marijuana plants, but it is for some other plants. If you work, or plan on working with other plants, it's a good habit to get into.
At this point clones are ready to be placed in an aeroponic or other type of cloner that does not use hydroponic media. For systems that require hydroponic media, follow the steps below.
After the plant cutting is ready, a drill bit that is slightly larger than diameter of the clone stem can prepare a hole in the media where the stem of the cutting will be inserted.
If root hormone is applied to the stem it will be wiped off during insertion and be of little value, unless you make a hole larger than the diameter of the stem.
After the holes in the hydroponic media are prepared, it is time to apply root hormone to the base of the clone stem to encourage the growth of new roots.
Dip the base of the stem into the gel, liquid, or powder until 1/2 to 3/4 inches (13 to 19 mm) of the base are covered. Gently tap off any excess powder if you are working with powder.
After application of the root hormone is completed, gently but firmly insert the stem of the cutting into your media 3/4 to 1 inch (20-30 mm) .
Make the hole with the drill bit slightly shallower than 3/4 to 1 inch (20-30 mm) so the clone is in the media nice and solid.
Then the clone is ready to be placed it in your cloner or hydroponic system, and provided with very mild nutrient solution or plain water.
Step By Step
A) Set up hydroponic system or cloner.
B) Get necessary items together.
C) Sterilize and clean up.
D) Choose a healthy mother plant.
E) Take clones from lowest branches.
F) Cut branch(es) off plant.
Fa) Optional, cut tip off branch, leave branch on plant.
G) Branch after it is cut off plant.
H) If necessary cut several clones from the branch.
I) Cut off excess leaves.
J) Clip large leaves to 1.5 inches/4 cm.
K) Put cuttings in container filled with water/nutrients.
L) Node where roots will emerge.
M) 45° angle cut about 1/4 inch (6 mm) below node.
Ma) 45° cut is not necessary for no media cloners.
N) Clones are ready for aeroponic/no media cloners.
Na) Or place in container filled with water/nutrients.
O) Prepare hole in media with drill bit.
P) Apply root hormone.
Q) Insert clone into media.
R) Put clone into hydroponic system or cloner.
List Of Materials
clean surface to work on
clean cloth or paper towel
small containers to hold water
hydrogen peroxide or rubbing alcohol
pH adjusted water or nutrient solution
hydroponic cloner or hydroponic system
cutting tools like sharp scissors, snips, etcetera
drill bit, slightly larger than diameter of clone stem
Cloning itself is a fairly quick procedure. You can easily prepare 10 or more clones in 30-60 minutes, but there is a bit of theory and preparation behind it. This section of the guide will look at the items required and why they are necessary.
*** root hormone *** Root hormone is applied to the base of the clone stem with clones that will grown in hydroponic media. This is done to encourage the growth of new roots.
Root hormone is not needed for aeroponic, or other cloners, that do not use hydroponic media. You can place the stems of clones in root hormone for a few minutes, so the clones absorb a bit, before putting new clones in a no-media type of cloner.
Most marijuana growers prefer liquid or gel root hormone but dry powder is also available. Dry powder does just as good of a job.
Be very careful not to let root hormone come into contact with any plant material other than the base of the clone stem. Getting a bit of root hormone on a plant leaf, or other part of the plant, can kill the entire plant.
Root hormone is optional but highly recommended unless you are experienced with cloning and know you can do a better job without it.
*** adequate lighting *** Adequate lighting in the cloning area is necessary, choose a spot that is well lit or supply supplementary portable lighting. There are no strong light, or special lighting, requirements for cloning.
*** hydroponic media *** There is hydroponic media designed specifically for starting clones and seeds. The mediums employed for the clones on this page were stg grow cubes, oasis rootcubes., rockwool starter cubes. All worked equally well for starting the clones.
Aeroponic and some other clone machines don't require any media. The base of the stem is suspended in a way that allows the area where the roots will grow, to come into direct contact with the water or nutrient solution.
If your cloner doesn't use hydroponic media you can ignore media requirements on this page, because they do not apply.
*** clean surface to work on *** Provide a clean surface to work on with enough room for all the accessories you will be working with. Sterilize the work surface by wiping with hydrogen peroxide or rubbing alcohol.
*** clean cloth or paper towel *** Cleanliness is extremely important when growing marijuana, especially when working with clones and young plants, because plants are most vulnerable to disease and other hazards when they are young.
Sterilize the scissors, containers, work surface, and anything else that will come into contact with your hands or the plant cuttings, with a clean cloth or paper towels in combination with hydrogen peroxide or rubbing alcohol.
Take a shower and put on clean clothes just before you start, then wash your hands with soap and hot water or put on a clean pair of latex gloves.
*** small containers to hold water *** Containers to hold water are necessary for putting cuttings into after they have been taken from a mother plant. Shot glasses, or other small glasses, are great for smaller cuttings while larger drinking glasses may be needed for longer cuttings.
*** hydrogen peroxide or rubbing alcohol *** Sterilize the scissors, containers, work surface, and anything else that will come into contact with your hands or the plant cuttings
Wipe them with a clean cloth or paper towels in combination with hydrogen peroxide or rubbing alcohol. Plants are generally more tolerant to hydrogen peroxide.
*** pH adjusted water or nutrient solution *** Fill the containers for putting cuttings into with pH adjusted water or mild hydroponic nutrient solution. The best source is nutrient solution from the system the clones will be grown in, after being prepared.
*** hydroponic cloner or hydroponic system *** A hydroponic cloner or hydroponic system is needed to put the clones in and grow them, after they have been prepared. Have it set up and running prior to taking clones to ensure there are no problems.
If the cloner or hydroponic system you have uses hydroponic media, prepare it so it is ready when the clones are. Media like rockwool has to be soaked in pH adjusted water before being utilized.
*** cutting tools like sharp scissors, snips... *** You will need a sharp cutting tool, or combination of tools, for cutting branches, leaves, stems, etcetera.
For these clones, pruning snips were used to do all cutting operations, with the exception of cutting branches off the mother plant, when pruning shears were needed.
If these are not available, you don't feel comfortable with them, or think you could do a better job with something else, consider sharp scissors, an x-acto knife, razor blades...
*** drill bit *** If your hydroponic system or cloner uses hydroponic media, a drill bit that is slightly larger than diameter of clone stem can prepare a hole in the media where the stem of the cutting will be inserted.
If root hormone is applied to the stem it will be wiped off during insertion and be of little value, unless you provide a little assistance. Something else that will be able to perform the task is ok if drill bits are not available.
Media like sure to grow might require making a small hole to open the media, followed by one or two larger bits in the same hole to enlarge it enough to provide clearance for the stem with root hormone on it.
Sure to grow is like a fabric, so it tends to bind larger bits. Media like oasis and rockwool are easy to make clearance holes with a single bit. Prepare the holes with a drill bit and your hand, no need for a drill.
Work to make holes with the drill bit when the hydroponic media is wet, it is easier to make the holes. Do not use dirty drill bits from your tool set. Get new clean bits, sterilize them before work, only work on plants with them.
Choosing A Mother Plant
Breeders might want to clone male plants but most marijuana growers are interested in cloning females.
When cloning marijuana plants, there are a few things to keep in mind when selecting a mother plant. Always choose a healthy plant as a mother plant.
Do not select a female just because she is tall, choose a shorter plant if that plant produces dense foliage (leaves) and branches with a smaller spacing between them on the main stem.
Growing After You Clone
Right after the clones have been prepared they have to be placed in a system where they can grow. If your hydroponic system and grow room can provide conditions that are within the tolerance of the plant, you can grow clones in it.
Clones grow quickest when humidity levels are maintained constantly over 70% and the air temperature is between 75-85°F/24-29°C. Providing those conditions can be difficult in a large area, so there are ways to make this easier.
A hydroponic cloner, also called a hydroponic cloning machine, is an option for starting clones. You can get fairly small ones, that take up little space, for reasonable prices. There are hydroponic cloners with a humidity dome, to keep humidity high, available.
Small hydroponic cloners can be put in a closet or other small confined space where it might be easier to maintain warm temperatures and humid conditions.
After the clones in a cloner have grown to a point where roots appear, they should be transplanted into a hydroponic system.
With an aeroponic or other type of cloner that does not require hydroponic media, the clones should be transplanted into solid media when the roots appear.
Lighting can be mild during this, the seedling stage, and turned on 16-18 hours a day. A minimum of 60 watts of fluorescent lighting is recommended at this time, but for faster growth metal halide or high pressure sodium can be applied.
It will take about 2-4 weeks for clones to go through the seedling stage, put down a solid root system and grow several pairs of leaves. Then they will enter the vegetative stage where they can really start growing.
The cuttings might look like they are going to dry up and die during the first 4 weeks, especially when the humidity and temperature are less than optimal. But once the roots and leaves start to develop, the plant will look healthy.
When the plant has developed a solid root system and several sets of leaves, the lighting can be increased to promote faster growth rates.
Optimal Conditions For Clones
Until roots are visible, hydroponic nutrient solution for clones should be very mild. Aim for an EC meter reading of about 100 µS (or 1.0 cf or 0.1 mS depending on the scale of your EC meter) or a TDS meter reading of 50 ppm (NaCl).
Some growers don't add any nutrients to the hydroponic water until new roots have started. There are hydroponic root enhancers that can be added to the nutrient solution to promote new roots to emerge quickly.
For the fast healthy growth of new clones in a hydroponic system, provide warm temperatures and moderate to high humidity levels.
Clones will grow quickest when humidity levels are maintained constantly over 70% and the air temperature is between 75-85°F/24-29°C.
However, maintaining these conditions can be difficult, and extra care will have to be taken because mold and other things that can harm plants might become a problem.
When the lights are on, air temperatures between 70-75°F/21-24°C and humidity levels over 60% are adequate, but growth will be a bit slower. Foliar feeding is an option to keep leaves from drying out when humidity levels are low. For monitoring conditions keep a hygrometer with built in thermometer close.
The water or nutrient solution temperature for clones should be monitored and maintained at about 68-70°F/20-21°C or slightly higher.
Some growers recommend 75-78°F/23-25°C water or nutrient solution temperatures for fastest growth.
To measure the temperature of water or nutrient solution, you can get an aquarium thermometer. Some pH, EC, TDS meters have a setting that allows them to take temperature readings of liquids.
1 --- Male plants are considered mother plants if they are cloned.
2 --- Some growers recommend supplying the mother plant with nutrients that have no nitrogen for three days prior to taking cuttings.
3 --- If possible, take cuttings from mother plants that have been growing 8 weeks. Most horticulture courses recommend plants be grown for at least 8 weeks before taking cuttings, but with marijuana, plants that have been growing for less time usually make good mother plants.
4 --- Some growers have one or more mother plants growing in a separate area, strictly for taking clones from. This is a good idea but might not be available to people with limited space.
5 --- Do the cloning around the same time as the lights shut off on the mother plants the clones were taken from. Let the clones recover in darkness and turn on the light at the same time the mother plant light turns on.
6 --- When taking clones from plants that were grown from seed and are still in the vegetative stage, and the sex of the mother plant is not yet known, you will have to take a cutting from each plant.
Be sure to mark the clone and mother plant in a way that lets you know they are related. Then when the mother plant starts to flower and you find out what sex it is, you will know what sex the cutting taken from that plant is.
7 --- Cuttings can be taken from healthy plants that are in the vegetative stage just before they are going to flower, do this before you start the 12/12 light cycle if you control when plants flower.
Prior to flowering it is a good idea to prune some of the lower branches off the plant, so there is room between the hydroponic media, or soil, and the bottom branches. This helps ensure good air circulation for the plant.
Lower branches often get very small amounts of light and produce a minimal amount of bud. This drains some energy from the plant that could be provided to larger buds. By pruning the bottom branches just before flowering, the rest of the plant benefits.
While doing this pruning, cuttings can be taken. Remember to let the mother plant recover for at least 3-5 days after pruning, before you start the 12/12 light cycle.
8 --- If the clones you take dry out and the leaves die, but the clones eventually grow normally, it might be that you left too much foliage when you took the clone.
To get faster growth rates, next time you clone cut back the leaves on the clones so that you could put a 2.5 inch tube around the clone, without the leaves touching the tube.
It takes energy for a new clone to support a large leaf system. Instead of focusing on new growth, the plant tries to support the old leaves.
You might be tempted, thinking more leaves will collect more light energy but too much foliage just delays the development of the new clone.
This is especially important under less than optimal conditions, like when the humidity around the clone is under 70%.
The clones taken in the images on this page could have had more of the leaf removed in order to grow faster, but the slower growth rate was known and taken into account.
9 --- Aeroponic, deep water culture, other cloners that keep the stem or media of a clone in constant contact with water/nutrient solution start clones quickest.
The cloner that these clones were started in could have been run in recirculating deep water culture, or ebb and flow mode.
The rdwc mode was chosen so the clones would produce roots faster. It is always best to get clones to root quickly. Once rooted they can better defend themselves and adapt to external forces.
10 --- Clones started in an aeroponic, deep water culture, or other hydroponic system that keeps the roots or media in constant contact with water or nutrient solution will not develop fine root hairs that roots in drier conditions will. Drier being hydroponic systems that do not keep the roots or media in constant contact with water or nutrient solution.
If clones that are started in a system that keeps the roots or media in constant contact with water or nutrient solution will be moved to a hydroponic system that supplies water or nutrient solution at intervals, the clones should be moved to the drier system when you can see the roots starting.
If you wait to transfer the clones, the roots will take longer to adapt to drier conditions and produce the fine root hairs, that they require in drier conditions.
For example, the clones taken when working on this page were started in a recirculating deep water culture cloner, where the media was in constant contact with nutrient solution.
Two days after the roots on the new clones started to form, the clones were switched to ebb and flow hydroponics, that supplies nutrient solution for short periods several times a day.
Most of the time the roots are not in contact with water or nutrient solution. After 3-5 days in the drier ebb and flow environment, the roots on all 6 plants had started to develop fine root hairs.
11 --- You might not want new clones to grow as fast as possible. If you have more than one growing area, the flowering area might be occupied for longer periods than other grow areas. Flowering plants take 6-12 weeks to mature, sometimes longer.
Clones from a female marijuana plant take about 4 to 8 weeks to go through seedling/vegetative stages and get to a point when they are ready to flower.
Clones might get to a point where they have matured and are ready to flower, but the flowering area is occupied by plants that still have a few weeks until they are ready to harvest.
To slow the growth rate of clones so they take longer to get to the point where they are ready to flower, you can leave more foliage on the clone when it is taken, provide less light, cooler, drier conditions for them.
Don't overdue things and try them one at a time, rather than all together. When taking the clones allow more of the leaves on the cutting to remain and do not cut the leaves back as far.
Keeping the light on 16 hours a day, nutrient solution temperature about 65-67°F/18-19°C, and the temperature of the surrounding air cool, but above 60°/16°C, when the light is on and above 50°F/10°C during the dark period.
If necessary, humidity levels can be kept between 40%-60% to further help slow growth. These measures will cause the plant some extra stress that they wouldn't go through if the conditions were closer to optimal.
But when done with moderation the plants will grow to be just as healthy, and flower as quickly/produce as large a crop, as those grown in warmer and more humid environments, they just grew slower.
In nature, it would be similar to a cool and dry spring. Don't overdo things or you could permanently damage or kill the plant. Even though you are slowing the growth rate, you still want the plant to be healthy.
Most marijuana strains are fine in less than optimal conditions, but if you think the plants are too stressed, you can raise the temperature and humidity to optimum levels.
For the quickest growth rates clones should be cut to 5-6 inches/13-15 cm in length. All the clones produced from the batch that the images on this page came from were 3-4 inches/8-10 cm and grown in cool, dry conditions in order to slow growth rates.
Also, when the clones were taken, the foliage could have been cut back a bit to speed growth of the new clone. The area these clones will flower in will be occupied for about 6-8 weeks after the clones are taken. In 6-8 weeks the clones would get too large if steps were not taken to retard growth.
When these clones are healthy robust plants that are ready to flower at 8 weeks old, they themselves will be cloned and mature into the next generation.
Another way to slow down the growth rate of clones is to take them from a mother plant that is flowering. The cuttings will have to switch from the flowering stage they are in, to the seedling stage. It will take them longer to mature than clones taken from a mother plant that was in the vegetative stage.Related Books
Grow Great Marijuana
Very good choice for simple and accurate instructions about growing hydroponic marijuana. Does not cover advanced techniques, but if you have no experience, this is the first book to look at.
Grow Great Marijuana
The Cannabis Encyclopedia
Easy to read with comprehensive focus on growing and consuming for medical and recreational purposes. This will be of interest to growers, patients, caregivers, consumers, or anyone interested in consuming, growing, or producing cannabis products.
Over 2,000 color images on 596 pages. Loaded with recent information covering all aspects of marijuana. The grow section explains hydroponics and soil growing, growing indoors, outdoors, and in greenhouses.
The Cannabis Encyclopedia