Step by Step: Learn How To Clone Your Marijuana Plants

The seedling growth stage lasts for about two to three weeks after seeds have germinated. Once a strong root system is established and foliage growth increases rapidly, seedlings enter the vegetative growth stage. When chlorophyll production is full speed ahead, a vegetative plant will produce as much green, leafy foliage as it is genetically possible to manufacture as long as light, C02, nutrients, and water are not limited. Properly maintained, marijuana will grow from one-half to two inches per day. A plant stunted now could take weeks to resume normal growth. A strong, unrestricted root system is essential to supply much needed water and nutrients. Unrestricted vegetative growth is the key to a healthy harvest. A plant's nutrient and water intake changes during vegetative growth. Transpiration is carried on at a more rapid rate, requiring more water. High levels of nitrogen are needed; potassium, phosphorus, calcium, magnesium, sulfur, and trace elements are used at much faster rates. The larger a plant gets and the bigger the root system, the faster the soil will dry out. The key to strong vegetative growth and a heavy harvest is supplying roots and plants with the perfect environment.

This seedling is in the early stages of vegetative growth.

Speed Rooter Canabis

This 'Euphoria' female has been in the vegetative growth stage for more than two months.

Vegetative growth is maintained with 16 or more hours of tight. 1 used to believe a point of diminishing returns was reached after 18 hours of light, but further research shows that vegetative plants grow faster under 24 hours of light. Marijuana will continue vegetative growth a year or longer (theoretically forever), as long as an 18-hour photoperiod is maintained.

Cannabis is photo periodic-reactive; flowering can be controlled with the light and dark cycle. This allows indoor horticulturists to control vegetative and flowering growth. Once a plant's sex is determined, it can become a mother, clone, or breeding male, and can be harvested or even rejuvenated.

Note: Plants show early male or female "pre-flowers" about the fourth week of vegetative growth. See "Pre-flowering" in Chapter Four and the sections here on pre-flowering male and female.

Cloning, transplanting, pruning, and bending are all initiated when plants are in the vegetative growth stage.

Clones and Cloning

Marijuana can be reproduced (propagated) sexually or asexually. Seeds are the product of sexual propagation; cuttings or clones are the result of asexual or vegetative propagation. In its simplest form, taking a cutting or clone involves cutting a growing branch tip and rooting it. Technically, cloning is taking one cell of a plant and promoting its growth into a plant. Marijuana growers commonly refer to a clone as meaning a branch of a cannabis plant that has been cut off and rooted.

Cloning reduces the time it takes for a crop to mature. Productive growers have two rooms, a vegetative/cloning room, about a quarter the size of a second room used for flowering. Smaller vegetative plants take up less space than older flowering plants. For example, a 250- or 400-watt metal halide could easily illuminate vegetative plants and clones that would fill a flowering room lit by three 600-watt HP sodiums. If the halide is turned off, fluorescent and compact fluorescent lamps are more economical and work well to root clones.

Combine eight-week flowering/harvest cycles with continuous cloning to form a perpetual harvest. One easy-to-implement scenario is to take two clones every four days, and harvest one ripe female every other day. Every time a plant is harvested, one or two rooted clones are moved from a constantly supplied vegetative room into the flowering room. This regimen gives a grower 30 flowering clones that are on a 91-day schedule. It takes 91 days from the time a clone is cut from the mother plant until the day it is harvested. Using this schedule, a grower would have 30 clones, 10 vegetative plants, and 30 flowering plants growing at all times. See chart next page.

Swiss retailers sold clones over-the-counter until the law changed in 2001. Now, Swiss growers have gone underground.

Clone production room in the basement of a Swiss retail store

Growth Stage


Number of plants


3 weeks



2 weeks



8 weeks




A sea of ciones share all genetic characteristics. They will all grow up to look like their mothers.

Two 'Queen Mother' plants will soon bear many, many clones.

Induce clones to flower when they are four to twelve inches tall to make most efficient use of HID light. Artificial light diminishes to the square of the distance, which means that foliage four feet away from the bulb receives one fourteenth as much light as if it were one foot away! Foliage that is shaded or receives less light grows slowly and looks spindly.

Short crops of clones in small containers are much easier to move and maintain than big plants in big containers. Short clones are also easy and efficient to grow in greenhouses and outdoors.

Well-illuminated, strong clones grow fast and have less chance of being affected by pests and diseases. Fast-growing clones develop more quickly than spider mites can reproduce. By the time a spider mite infestation is noticed and sprayed, the plants are a few weeks from harvest. Clones are also easy to submerge in a miticide when small.

Experiments with clones are consistent and easy to control. Genetically identical clones respond the same to different stimuli, such as fertilizer, light, bending, etc. After experimenting on several crops of clones from the same mother, a grower has a very good idea what it takes to make them grow well.

Mother Plants

Any plant can be cloned, regardless of age or growth stage. Take clones from mother plants that are at least two months old. Plants cloned before they are two months old may develop unevenly and grow slowly, Clones taken from flowering plants root quickly but require a month or longer to revert back to vegetative growth. Such rejuvenated clones occasionally flower prematurely, and buds are more prone to pest and disease attacks.

Any female can become a mother. She can be grown from seed or be a clone of a clone. 1 interviewed several growers who made clones of clones more than 20 times! That is, clones (C-l) were taken from the original female grown from seed. These clones were grown in the vegetative stage, and clones (C-2) were taken from the first clones (C-l). Blooming was induced in (C-l) two weeks later and (C-2), grown in the vegetative stage. Then, clones (C-3) were taken from the second clones (C-2). This same growing technique is still going on with clones of clones well past (C-20) and there has been no apparent breakdown in the potency or the vigor of the clone. However, if mothers suffer stress, they produce weak clones. Mothers that are forced to flower and revert back to vegetative growth not only yield less, they are stressed and confused. Clones that grow poorly are generally the result of poor, unsanitary cloning practices.

Week Old Cannabis Clones

A clone is an exact genetic replica of the mother plant. Each mother's cell carries a DNA blueprint of itself. Radiation, chemicals, and poor cultural practices can damage this DNA. Unless damaged, the DNA remains intact.

A female plant will reproduce 100 percent females, all exactly like the mother. When grown in the exact same environment, clones from the same mother look alike. But the same clones subjected to distinct environments in different grow rooms will often look different.

A six-month old plant produces more cannabinoids than a one-month old plant. By cloning, a horticulturist is planting a THC-potent plant that will continue to grow in potency at a very rapid rate. A month-old rooted clone acts exactly like a four-month-old plant and can be induced easily to flower with a 12-hour photoperiod.

Keep several mother plants in the vegetative stage for a consistent source of cloning stock. Start new mothers from seed every year. Give mother plants 18-24 hours of light per day to maintain fast growth. For best results, give mothers about ten percent less nitrogen, because less nitrogen promotes rooting in clones.

This young 'Shaman' has already shown female pre-flowers and can become a mother plant.

Swiss greenhouse grower nurtures clones in lower beds and keeps mothers in bright light in upper bed.

Mother plants are growing in large, individual hydroponic containers for easy culture and maintenance.

The root system on this heavily producing mother plant is white-very strong and healthy.

Mother plants must stay very healthy to be able to produce many clones. The roots on this mother are very healthy!

Negative points

Clones grow slower than Fl hybrid plants grown from seed. An Fl hybrid is the heterozygous first filial generationpollen and ovule. Fl hybrids have "hybrid vigor" which means that this cross will grow about 25 percent bigger and stronger than cuttings. Hybrid vigor also makes plants less susceptible to pest and disease problems.

Always start with the best mothers you can find. A mother plant yields clones in her image. If the mother plant lacks potency, harvest weight, or is not pest and disease resistant, the clone shares her drawbacks. These weaknesses are compounded when growing only one strain. An unchecked pest or disease infestation could wipe out the entire crop,

Some growers have a difficult time learning to make clones. If this is the case, continue to work through the little problems one step at a time, and you will learn. Some people have a little longer learning curve when cloning is involved. Take five to ten practice clones before making a serious cloning. You can also work with strains that are easy to clone, as illustrated in the chart below.

Plants that are easy to clone

Most Skunk and Indtca strains are easy to clone.

Growers and sick plants cause most clone rooting problems. Weak plants that lack vigor provide slow-rooting weak clones. Poor growing conditions also affect clone strength.

Harder to clone

Ruderalis Itidica and Ruderalis Skunk do not make suitable mother plants due to their auto-llowering capability. Outdoor strains with a slight tendency to pre-sex in an 1Bhr photo period include: Early Girl, Early Skunk and many others. Check with seed companies for details. But early flowering does not exclude them as mother plants.

Getting Ready

Cloning is the most traumatic incident cannabis plants can experience. Clones go through an incredible transformation when they change from a severed growing tip to a rooted plant. Their entire chemistry changes. The stem that once grew leaves must now grow roots in order to survive. Clones are at their most tender point in life now.

Clones quickly develop a dense system of roots when stems have a high carbohydrate and low nitrogen concentration. Build carbohydrate levels by leaching the growing medium with copious quantities of water to flush out nutrients. The growing medium must drain very well to withstand heavy leaching without becoming waterlogged. Reverse foliar feeding will leach nutrients from leaves, especially nitrogen. To reverse foliar feed, fill a sprayer with clean water and mist mother heavily every morning for three or four days. Older leaves may turn light green; growth slows as nitrogen is used and carbohydrates build. Carbohydrate and hormonal content is highest in lower, older, more mature branches. A rigid branch that folds over quickly when bent is a good sign of high carbohydrate content.

Clones from lower branches root the easiest because they contain more of the proper hormones.

Integrity in parents

  1. Maintain 18-24-hour day photoperiod
  2. Keep plants healthy
  3. Grow for 6-9 months
  4. Repot
  5. Crow hydroponically

Hormone content is different in different parts of a plant. Root growth hormones are concentrated near the base of the plant close to the main stem. This is the oldest portion of the plant and is where most root hormones are located. The top of the plant contains older hormones; cuttings taken from this part root slowly.

While rooting, clones require a minimum of nitrogen and increased levels of phosphorus to promote root growth. Sprays should be avoided during rooting as they compound cloning stress. Given good instruction and a little experience, most growers achieve a consistent; 100 percent clone survival rate.

Large cuttings with large stems packed with starch grow roots slower than small clones with small stems. The excess starch in moist substrate also attracts diseases. Thin-stemmed clones have fewer reserves (accumulated starch), but they only need enough reserve energy to initiate root growth.

Small clones with few leaves root faster than big cuttings with many leaves, At first leaves contain moisture, but after a few days, the stem is no longer able to supply enough moisture to the leaves, and the clone suffers stress. A small amount of leaf space is all that is necessary for photosynthesis to supply enough energy for root growth.

These 'Ortega' clones were taken on August 25. Now they are rooted and ready to transplant.

Cut from Young

Cut from Old

Cell division starts

Day 4

Day 6

First root nubs form

Day 6

Day 10

Roots start to grow

Day 7

Day 20

Enough roots to transplant

Day 14

Day 28

This chart shows average times for roots to grow from the cambium. Note clones taken

from younger growth root about twice as fast as those taken from older growth.


An embolism is a bubble of air that gets trapped in the hole in the stem. Embolisms occur when you take big clones and lay them on the counter before placing in water or a growing medium. When an embolism happens, fluid flow stops, and clones die. After taking cuttings, immediately dip them in water or a growing medium to prevent air from getting trapped in the hollow stems. Eliminate the threat of an embolism by taking cuttings under water.

Clones root well within a pH range of five to six. Aeroponic clone gardens normally do best with a pH of five to five and a half. Most diseases grow poorly below these pH levels. Always make sure there is plenty of air in the rooting medium; this will stimulate root growth.

Do not kill clones with kindness and fertilizer. At best, giving clones an excess dose of fertilizer causes rooting to be delayed. In fact, a good dose of ammonium nitrate, a common fertilizer, will stop root hairs from growing.

If an infestation occurs, apply aerosol pyrethrum. Remember, all pesticides, natural or not, are phytotoxic. Spraying cuttings is a bad idea in general. If you must use sprays, use natural organic sprays, apply them when it is cool, and keep their use to a minimum.

Use anti-desiccant sprays sparingly, if at all, and only if a humidity dome is unavailable. Anti-desiccant sprays clog stomata and can impair root growth in clones.

Do not over-water clones. Keep the medium evenly moist, and do not let it get soggy.

Any kind of stress disrupts hormones and slows rapid growth

Keep the cloning area clean. Do not take clones where fungus spores and diseases are hiding! Pythium is the worst! Pythium flourishes in high temperatures and excessive moisture. Mites, whiteflies, thrips, etc., love weak tender clones. Remove infested clones from the room. Cooler conditions, 65-78°F (18-25°C), slow mite and fungal spore reproduction and allow you to avert an infestation.

Do not use fertilizers on clones or seedlings

Rooting Hormones

Root-inducing hormones speed plant processes. When the stem of a cutting develops roots, it must transform from producing green stem cells to manufacturing undifferentiated cells and, finally, to fabricating root cells. Rooting hormones hasten growth of undifferentiated cells. Once undifferentiated, cells quickly transform into root cells. Three substances that stimulate undifferentiated growth include napthalenaecetic acid (NAA), indolebutyric acid (IBA) and 2, 4-dichlorophenoxyacetic acid (2, 3 DPA). Commercial rooting hormones contain one, two, or all of the above synthetic ingredients and often include a fungicide to help prevent damping-off.

Rooting hormones are available in liquid, gel, or powder form. Liquid and gel types penetrate stems evenly and are the most versatile and consistent. Powdered rooting hormones adhere inconsistently to stems, penetrate poorly, spur uneven root growth, and yield a lower survival rate.

Rooting Hormone

Algimin ii Maxicrop


Dry kelp product Liquid seaweed


NO IBA or NAA. Soak cuttings overnight in a solution of two ounces AlgimilWi' to one gallon of water. Alter planting, continue watering with this solution.

CI on ex if

First cloning gel

Blend of seven vitamins, eleven minerals, two antimicrobial agents, 30O0 ppm rooting hormones. Gel seals cutting tissues, reducing chance of infection and embolisms.

Dtp-N-Grown Earth Juicc Catalyst n

IBA, NAA, anti-bacterial

Cost is one penny per loo cuttings. Organic, derived from oat bran, kelp, molasses, vitamin B complexes, amino adds, hormones, arid low levels of nutrients.

Norm ex

IBA based powder

Available in six different strengths ranging from 1000 ppm to 15,000 ppm.



Powder available in three strengths: 1000, 3000, and 0000 ppm.

Nitrozyme fl>

Natural product

Seaweed extract, contains cytokinins, auxins, enzymes, gibbcrejlins, and ethylenes. Spray Nitrozyme on mothers two weeks before taking cuttings.

Olivia's Cloning Solutionx Olivia's Cloning Gel

IBA, anti-fungal agents, nutrients

Very high success rate.

Rhizopon AA H' (Rhizopon B.V.)


World's largest company devoted to research and manufacture of rooting products. Powder and water-soluble tablets in strengths from fiOO to 20,000 ppm.


IBA vitamins, hormones

From Tecknaflora is one of lite favorite products in North America.

Vita Grow


Customers say "you could root a popsicle stick"

Warning! Sonic products ¡ire not recommended for use willi edible plants. Head the Libel carefully before deciding (o use a product.

Liquid rooting hormones can be mixed in different concentrations. Always mix the most dilute concentration for softwood cuttings. Apply any rooting hormone containing IBA only once. If exceeded in concentration or duration, IBA applications impair root formation. As soon as cuttings are taken, clones start dispatching rooting hormones to the wound. They arrive in full force in about a week. The artificial rooting hormone fills the need until natural hormones take over.

Give cuttings a 5-15 second dip in concentrated solutions of IBA and MA A, 500-20,000 ppm. With a quick dip, stems evenly absorb the concentrated hormone.

Relatively new to the market, gels have caught on everywhere. They are easy to use and practical, but are not water soluble. Once applied, gels hold and stay with the stem longer than liquids or powders.

Rooting powders are a mixture of talc and lliA and/or NAA and are less expensive than liquids or gels. To use, roll the moistened end of your cutting in the powder. Apply a thick, even coat. To avoid contamination, pour a small amount into a separate container, and throw away any excess. Tap or scrape excess powder off the cutting; excess hormones can hinder root growth. Make a hole bigger than the stem in the rooting medium. If the hole is too small, the rooting powder gets scraped off upon insertion.

You can also spray clones with a single foliar spray of dilute 1BA (50-90 ppm). Be careful to spray just enough to cover leaves. Spray should not drip off leaves. An IBA overdose slows growth, makes leaves dwarf, and could even kill the clone.

Some growers soak their cuttings in a dilute solution (20-200 ppm IBA and/or NNA) for 24 hours. But I have seen few growers use this time consuming technique.

To determine the rooting hormone concentration in parts per million, multiply the percentage listed by the manufacturer by 10,000. For example, a product with 0.9% IBA contains 9000 ppm IBA.

An all-natural, root-inducing substance is willow (tree) water. The substance in all willow trees that promotes rooting is unknown, but repeated experiments have proven willow water promotes about 20 percent more roots than plain water. This willow water is mixed with commercial rooting hormones for phenomenal results.

To make willow water rooting compound, find any willow tree and remove some of this year's branches that are about one and a half inches in diameter. Remove the leaves, and cut the branches into one-inch lengths. Place one-inch willow sticks on end, so a lot of them fit in a water glass or quart jar. Fill the jar with water, ard let it soak for 24 hours. After soaking, pour off the willow water, and use it for rooting hormone. Soak the marijuana clones in the willow water for 24 hours, then plant in rooting medium, If using a commercial liquid rooting hormone, substitute the willow water in place of regular water in the mix.

Cef all cloning supplies ready before starting.

Canna products and several other commercial products contain Trichoderrna bacteria. The bacterium causes roots to grow and absorb nutrients better. To learn more about

Avoid problems:

Keep the work area clean. Wash work surfaces and tools before starting. Have grow medium ready.

Prepare mother plant (scion).

Take clones.

Store unused clone.

Insert (stick) cutting in growing medium or aeroponics system.

Place clones under humidity tent.

Look for root growth.

Transplant when roots emerge from root cube or medium.

Harden-off by gradually exposing to new environment.

This beautiful 'Stinky Pinky' mother is just two and a half months old.

Crow More Roots

Split the stem of clones tn expose more of the cambium layer just under the "skin" of the stem. II is the only place that generates new roots.

Exposing the cambium layer causes many roots to grow there. Lightly scraping away the outer layer of the stem to expose only the cambium allows hormones to concentrate where roots start. Splitting the clones' stem exposes more surface area to grow roots. Both practices increase the number of healthy roots, but rooting time is a few days longer.

After the cutting has been trimmed and scraped, dip the bare stem into a rooting hormone. Mow it is ready to "stick" into the substrate.

Split the stem to initiate more surface area for roots to grow.

it, check out the Carina web site

Before Making Clones

Making clones or cuttings is the most efficient and productive means of cannabis propagation for small growers, both indoors and out. Once females have been distinguished, you are ready to practice the simple, productive art and science of cloning.

Disinfect all tools and working surfaces to kill bacteria, fungi, viruses, and other diseases already present. Use sharp scissors, razor, or razor blade dipped in alcohol, vinegar, or bleach (five to ten percent solution). Wash your hands thoroughly beforehand.

Make sure to have all cloning supplies within arm's reach-rooting cubes, hormone, razor or scissors, humidity dome, etc.-before you start to take clones.

Cloning: Step-by-Step

Step One: Choose a mother plant that is at least two months old. Some varieties give great clones even when pumped up with hydroponics and fertilizer. If a variety is difficult to clone, leach the soil with two gallons of water for each gallon of soil every morning for a week before taking clones. Drainage must be good. Or mist leaves heavily with plain water every morning. Both practices help wash out nitrogen. Do not add fertilizer.

Step Two: With a sharp blade, make a 45-degree cut across firm, healthy 0.125-0.25-inch-wide (3-6 mm) branches, two to four inches four inches (3-5 cm) in length. Take care not to smash the end of the stem when making the cut. Trim off two or three sets of leaves and growth nodes so the stem can fit into the soil. There should be at least two sets of leaves above the soil line and one or two sets of trimmed nodes below ground. When cutting, make the slice halfway between the sets of nodes. Immediately place the cut end in water. Store cut clones in water while making more clones.

Trim off one or two sets of leaves

Hold cut clones in a glass of water until you are ready to dip in hormone and plant.

Step Three: Rockwool and Oasis'''1 root cubes are convenient and easy to maintain and transplant. Fill small containers or nursery flats with coarse, washed sand, fine vermiculite, soilless mix, or, if nothing else is available, fine potting soil. Saturate the substrate with water. Use an unsharpened pencil, chop stick, nail, etc., to make a hole in the rooting medium-a little larger than the stem. The hole should stop about one-half inch from the bottom of the container to allow for root growth.

Place a tray containing rooting cubes or plugs into a standard nursery rooting flat. If none exist, make holes through three-fourths of the cube for clone stems.

Fill rockwool tray with water, pH 5-6. Always use strong plastic trays.

Crow clones until they are well-rooted. Always remember to label clones when planting.

Dip trimmed stem into the rooting gel or liquid hormone. Make sure stem is covered with the proper amount of rooting hormone.

Place the stem covered with rooting hormone into the root cube.

growing medium is in full contact with the stem.

Step Four: Use a rooting hormone, and mix (if necessary) just before using. For liquids, use the dilution ratio for softwood cuttings. Swirl each cutting in the hormone solution for 5-15 seconds. Place the cuttings in the hole in the rooting medium. Pack rooting medium gently around the stem. Gel and powder root hormones require no mixing. Dip stems in gels as per instructions or roll the stem in the powder, Wiien planting, take special care to keep a solid layer of hormone gel or powder around the stem when gently packing soil into place.

Step Five: Lightly water until the surface is evenly moist. Keep cuttings moist at all times. Clones have no roots to bring water to leaves. Water arrives from leaves and the cut stem until roots can supply it. Water as needed to keep growing medium evenly moist. Do not let it get soggy.

Step Six: Clones root fastest with 18-24 hours of fluorescent light. If clones must be placed under an HID, set them on the perimeter of the garden so they receive less intense light; or shade them with a cloth or screen. A fluorescent tube six inches above clones or a 400-watt metal halide lamp four to six feet away supplies the perfect amount of light for clones to root. Cool white fluorescents (or a combination of warm and cool white) are excellent for rooting.

Humidity domes fit over flats of clones to retain humidity. The domes on the right are covered with lightweight Agronet to lower light on new clones.

Hooting Clones

Hooting Clones


A fogger in the cloning room will ensure humidity stays above 95 percent.

To lower transpirationi, cuf clone leaves in half before sticking.

Step Seven: Clones root fastest when humidity levels are 95-100 percent the first two days and gradually reduced to 80-85 percent during the following week. A humidity tent will help keep humidity high. Construct the tent out of plastic bags, rigid plastic, or glass. Remember to leave openings for air to flow in and out so little clones can breathe. If practical, mist clones several times a day as an alternative to the humidity tent. Remove any sick, rotting, or dead foliage.

Cut leaves in half to lower transpiration surface and to keep them from overlapping. Moisture that could foster fungus is often trapped between overlapping leaves. Keep the grow medium evenly moist so there is enough moisture to prevent cut leaves from bleeding out plant sugars that attract diseases.

Step Eight: Clones root faster when the growing medium is a few degrees warmer than the ambient air temperature. A warmer substrate increases underground chemical activity, and lower air temperature slows transpiration. For best results, keep the rooting medium at 75-80°F (24-27°C). Crowing medium temperatures above 85°F (29°C) will cause damage. Keep the air temperature 5-10°F (3-5.5°C) cooler than the substrate. A warmer growing medium coupled with cooler ambient temperature slows diseases and conserves moisture. Misting clones with water also cools foliage and slows transpiration to help traumatized clones retain moisture unavailable from nonexistent roots.

Put clones in a warm place to adjust air temperature and use a heat pad, heating cables, or an incandescent light bulb below rooting cuttings.

Step Nine: Some cuttings may wilt but regain rigidity in a few days. Clones should look close to normal by the end of the week. Cuttings that are stil! wilted after seven days may root so slowly that they never catch up with others. Cull them out, or put them back into the cloning chamber to grow more roots.

An incandescent light bulb attached to a rheostat provides exacting control of bottom heat,

This large clone has been rooting for a week. The expert grower makes sure the climate is perfect, so clones suffer no stress.

Strong clone in an aeroponic clone garden has a mass of roots and is ready to plant.

Step Ten: In one to three weeks, cuttings should be rooted. Signals they have rooted include yellow leaf tips, roots growing out drain holes, and vertical growth of the clones. To check for root growth in flats or pots, carefully remove the root ball and clone to see if it has good root development. For best results, do not transplant clones until a dense root system is growing out the sides and bottom of rooting cubes.

Cuttings are always strong and healthy-looking after you take them. After five or six days, leaves may start to change color, Leaves stay small and often turn a deeper shade of green. After about a week, lower leaves may start to yellow if their nutrient levels dissipate.

A week after being taken, clones' stems will develop stubby callused roots called primor-dia. The primordia are semi-transparent to white and should look healthy. Clones produce very little green growth during this process. Once the root and vascular transport system is in place and working properly, clones are able to experience explosive growth with the proper care.

Rooting clones can handle increasingly more light as roots grow. Move the fluoresced lamps to two to four inches above plants when roots form. Fertilize with a mild fertilizer solution when all clones have started vegetative growth.

Any sign of slime, pests, or disease means there are problems, and clones should be removed from the garden.

Transplant only the strongest, well-rooted clones. (See "Transplanting" below.) Slow-rooting clones should be kept in the cloning chamber or culled out. Do not move clones below bright light until they have fully developed root systems. Once transplanted, clones are ready to harden-off (see "Transplanting" below).

1. Make 2 cuttings

2. Label each cutting

Cloning the apex of the tip

Swiss cloning expert is removing the tip of a mother plant to clone in an agar solution. Such clones are easy to maintain for long periods.

Setup a vegetative pre-growing area that is lit with an HID or bright compact fluorescent lamp for the rooted clones. Place them in this area to let them grow the first week or two of vegetation. This area needs to be just big enough to accommodate plants from the time they are a few inches tall until they are about a foot tall and ready to he moved into the flowering room.

Sequence of cloning for sex

  1. Make 2 cuttings
  2. Label each cutting
  3. Give 12 hours of light while rooting
  4. Cutting will determine sex in 2-3 weeks

Air layering

There is a good sequence of air layering in Marijuana Botany, by Robert C Clarke. To date, I have never seen anybody use this technique. It is interesting, but normally not necessary. Cannabis is easy to root or clone.

Cloning for Sex

Determine plant sex accurately, 100 percent of the time, by "cloning for sex." To clone for sex, take two cuttings (in case one dies) from each parent plant in question. Use waterproof labels and an indelible marker to identify sets of clones and corresponding parents.

Give rooting clones a 12-hour light/dark regimen. After a 12-hour day, set clones in a dark closet, or place a box over them. The dark period must be total and uninterrupted to induce flowering. Clones usually show sex within two weeks. Cull out all males except those used lor breeding. Flower little females, and keep their mothers growing under 18-24 hours of light.

Growers with only one room root clones in a nursery flat, and cover it with a light-tight cardboard box for 12 hours every night Remove the cardboard box after the lights go out to increase air circulation and ventilation.

Clones from a Flowering Female

You can clone a favorite flowering plant, but it is difficult. Clones take longer to root, and results are not always the best. Powerful flowering hormones must be reversed, and rooting hormone signals must be sent. Now is the time to give plants 24 hours of light to signal them to grow.

Cut clones from the lower green branch tips. Cut a one to two-inch-long (3-5 cm) stem. Trim off flowers and lower leaves. Keep two or three green leaves. If leaves have yellowed, survival chances diminish exponentially.

You can take clones from flowering plants and revert them to vegetative growth once rooted.

The earlier in the flowering stage cuttings are taken, the more rapid the rooting and the re-vegetation rate. Once a plant reaches the senescence point, growth hormones have dissipated, leaving not enough to initiate roots.

Storing Clones

To store cuttings for later use, wrap recently cut and trimmed stems in a damp cloth or paper towel. Put the wrapped clones into a plastic bag, and store in the refrigerator. On a daily basis, remove the water that condenses inside the bag in the cool refrigerator. Keep the temperature above 40°F (5°C). Temperatures below this level may cause plant cells to rupture. Cuttings should last in the refrigerator for about three weeks.

Clonex Root Matrix, a Growth Technology product, is a gel that allows cut clones to root and be held until they are needed.


When plants are too big for their containers, they must be transplanted to continue rapid growth. Inhibited, cramped root systems grow sickly, stunted plants. Signs of root bound plants include slow, sickly growth and branches that develop with more distance between limbs. Severely root-bound plants tend to grow straight up with few branches that stretch beyond the sides of the pot. To check for root-bound symptoms, remove a plant from its pot to see if roots are deeply malted on the bottom or surrounding the sides of the pot.

When growing short plants that reach full maturity in 90 days, there is little need for containers larger than three gallons (11 L). Large mother plants will need a large pot if they are kept for more than a few months.

In this container, roots are growing mainly around the sides and along the bottom. This plant is ready to be transplanted.


Mix the clone dip, and use a rag to cover and contain soil when dipping.

Submerge the entire clone in the dip to ensure miticide covers all foliage.

Remove the clone, and shake off excess dip before transplanting.

Dip rooted clones into a miticidal/fungicid-al solution before transplanting and before moving into the flowering room.

Mix a miticidal/fungicidal dip (I like Einstein Oil) to disinfect clones before sticking them in the growing medium. Fill a container with low pH water (5-6) and add a natural fungicide such as hydrogen peroxide in a two percent solution. Or include a ten percent mix of chlorine or vinegar. Do not mix vinegar and chlorine! The resulting gas is hazardous. See "Transplanting."

Transplant into the same type or similar growing medium; otherwise, a water pressure differential could develop between the different mediums, which slows water movement and causes slow root growth. Starling seeds and clones in root cubes or peat pots makes them easy to transplant. Set the cube or peat pot in a hole in the growing medium, and make sure growing medium is in firm contact. Remember to keep root cubes and substrates evenly moist after transplanting.

Transplanting is the second most traumatic experience after cloning. It requires special attention and manual dexterity. Tiny root hairs are very delicate and may easily be destroyed by light, air, or clumsy hands. Roots grow in darkness, in a rigid, secure environment. When roots are taken out of contact with the soil for long, they dry up and die.

Transplanting should involve as little disturbance to the root system as possible. Water helps the soil pack around roots and keeps them from drying out, Roots need to be in constant contact with moist soil in order to supply water and food to the plant

After transplanting, photosynthesis and chlorophyll production are slowed, as are water and nutrient absorption via roots. Transplant late in the day so transplanted plants will have all night to recover. Transplants need subdued light, so foliage can grow at the rate roots are able to supply water and nutrients. Give new transplants filtered, less-intense light for a couple of days. If there is a fluorescent lamp handy, move transplants under it for a couple of days before moving them back under the HID or outdoors to harden-off.

Ideally, plants should be as healthy as possible before being traumatized by transplanting. But, transplanting a sick, root-bound plant to a bigger container has cured more than one ailing plant Once transplanted, cannabis requires low levels of nitrogen and potassium and increased quantities of phosphorus. Any product containing Trichoderma bacteria or Vitamin B, will help ease transplant shock. Plants need a few days to settle in and re-establish a solid flow of fluids from the roots throughout the plant. When transplanted carefully and disturbed little, there will be no signs of transplant shock or wilt, within two inches (5 cm) of the top.

Roots showing through a rooting cube means cuttings are ready to transplant

Double potting is a simple transplanting technique that disturbs roots very little. To double pot a plant, cut the bottom out of a root-bound pot, and set on top of another bigger pot of soil. Roots grow down into second pot.

Transplanting Step-by-Step

Step One: Water clone with half-strength Trichoderma bacteria Vitamin B two days before transplanting.

Step Two: Fill the three-gallon (11 L) container with rich potting soil or soilless mix to

Step Three: Water growing medium with a mild, quarter-strength hydroponic fertilizer solution until saturated and solution drains freely out the bottom.

Step Four: Carefully remove the root ball from the container. Place your hand over top of container with the stem between your fingers; turn it upside down, and let root ball slip out of pot into your hand. Take special care at this point to keep the root ball in one integral piece.

Half Strenght Tricoderma Bacteris Mix

Carefully remove seedlings from containers. These seedlings were kept moist and moved quickly to minimize exposure to air and light. Growers used Vitamin S, solution to ease transplant shock.

Step Five: Carefully place the root ball in the prepared hole in the three-gallon (11 I) container. Make sure all roots are growing down.

Step Six: Backfill around the root ball. Gently, but firmly, place soil into contact with root ball.

Step Seven: Wiiter with half-strength fertilizer containing Trichoderma bacteria or Vitamin Br Soil should be saturated-not waterlogged-and drain freely. If rooting cube and new substrate are not identical, pay special attention to moisture levels. Let rock-wool dry out enough so that roots penetrate new growing medium in search of moisture.

Step Eight: Place new transplants on the perimeter of the HID garden or under a screen to subdue sunlight for a couple of clays. Once transplants look strong, move them under full light.

Step Nine: Fertilize soilless mixes after transplanting with a complete hydroponic fertilizer that contains soluble chelated nutrients. New potting soil usually supplies enough nutrients for a couple of weeks before supplemental fertilization is necessary.

Week Vegitive

This clone grew in a four-inch (10-cm) pot and is ready to he transplanted

Week Vegitive

Transplanting this clone grown in rockwool into soil or soilless mix is simple and easy. Remove the rockwool's plastic covering before setting the clone in a pre-made hole in substrate.

Step Ten: Minimum Container Size chart below.

Minimum Container Size Plant age Container size

  • 1-3 weeks root cube
  • 2-6 weeks 4-inch (10 cm) pot 6-8 weeks 2-gallon (7.5 L) pot
  • 2-3 months 3-gallon (11 L) pot
  • 3-8 months 5-gallon (19 L) pot 6-18 months 10-gallon (38 L) pot

Seedlings and clones can also be transplanted directly into a three- to five-gallon (11-19 L) pot, a system which requires fewer containers and involves less work and less possible plant stress. The larger volume of soil holds water and nutrients longer and requires less frequent watering. When clones and seedlings are transplanted directly into a five-gallon (19 L) container, the roots grow down, out, and around the container walls and bottom. In fact, the majority of roots grow out of the soil and form a layer behind the container wall.

To encourage roots to develop a dense compact system, transplant just before they have outgrown their container. Transplanting a well-rooted clone in a root cube into a four-inch (10-cm) pot and transplanting the four-inch (10-cm) pot into a three-gallon (11 L) pot or grow bag causes roots to develop a more extensive system in a small ball of growing medium. Successful transplanting causes minimal stress. Most marijuana crops are in the ground for such a short time that bungled transplanting costs valuable recuperation time and loss in production.

Transplant clones and seedlings into raised beds and large planter boxes directly from four-inch (10-cm) pots. As many as 20 plants can be transplanted into a 24 x 24 x 12-inch (6 ! x 61 x 30 cm) planter, but six to twelve plants will yield about the same dry weight of buds. Once plants start crowding and shading one another, bend stems outward and tie them to a trellis attached to the planter.

This clone was transplanted directly into a large container at the Cannabis College in Amsterdam.

Large planters require less maintenance. The larger mass of soil retains water and nutrients much longer and more evenly. One downside is that all plants must receive the same water and diet.

Three-gallon (11 L) containers are the ideal size for two- to three-foot-tall (60-90 cm) plants. Larger pots are usually unnecessary because plants grow no longer than a week or two in the vegetative stage and six to ten weeks flowering. Smaller three-gallon (11 L) pots are easy to move and handle. Roots also grow less during flowering. By the time a plant is potbound, it is ready to harvest. I used to recommend up to a five-gallon (19 L) container for plants that are harvested after 90 total days of life. 1 now believe this is a waste. While the smaller containers require


Hardening-off is the process of tough-ening-up clones and seedlings. During the rooting process, leaves supplied much of the moisture for the clone. Mow, healthy white new roots are supplying moisture to the clone. Check for root damage. Brown roots are rotting and lack oxygen. Thin hair-like dark roots are dried out. Once damaged, roots remain damaged. New roots must grow to replace damaged roots. Cull out any clones with damaged roots, because they will grow slowly. The protective wax coating must also grow back on leaves. It is best to acclimate rooted clones to the grow room over the course of a week.

These beautiful little seedlings were started indoors under a fluorescent lamp.

Gradually hardening-off clones will assure moves them outdoors for a few hours every they suffer a minimum of stress and con- day to harden-off and acclimate to the out-tinue to grow rapidly. door environment.

Harden off the strong ones, and introduce them to the real world-the grow room where they will see photosynthetically active response (PAR) at full value and nutrients that make their cells quiver. Now is the time to pre-grow clones before placing them into the flowering room.

Foliage loses its protective wax coating when it is pampered during cloning, so it is very tender now. New roots must start to transport water via the stems to the leaves. The roots and moisture-transport system start to work on strong, healthy clones first. Clones that lag behind now should be tossed out, because they will always be slow. You can let them root longer and not transplant them until adequate roots develop.

This female was pruned and bent to keep a low profile and open up the center of the plant.

Mother plants are much larger, grow longer, and can require containers up to 30 gallons (115 L) in size. However, mother plants grow quite well in five or ten-gallon (19-38 L) hydroponic containers for a year or longer. If you plan to keep a mother plant for more than a few months, grow it hydroponically in its own container for best results.

Pruning and Bending

Pruning and bending a plant redirects growth hormones. Pruning affects the plant more drastically than bending. Selective pruning and bending allow us to manipulate auxin hormone levels in branch and (lower tips. Removing or bending a branch or branch tip causes hormonal balances to shift. Cutting the meristem (top growth tip) of a cannabis plant will diffuse auxins and cause greater concentrations in lower branch tips. Bending a growing tip changes hormone concentrations less than pruning.


Always use dean instruments when pruning. A straight razor, single-edge razor blade, a sharp pair of pruners, or a pair of scissors all work well. Sanitize clippers and blades between cuts by dipping in rubbing alcohol. Use indoor pruners only in the indoor garden. Pruners used outdoors have everything from spider mites to fungus spores on them. If outdoor clippers must be used, dip in rubbing alcohol to sterilize before making cuts.

After pruning, the open wound invites diseases and pests. Wash your hands and tools before and after pruning. Make cuts at a 45-degree angle to discourage moisture from sitting on wounds.

Avoid pruning up to a month before inducing flowering. Since pruning diffuses floral hormones, flowering is retarded. If heavily pruned shortly before flowering, peak maturation is delayed for a week or longer. It takes a month or longer for hormones to build up to pre-pruning concentrations.

Leave leaves alone! Removal of healthy leaves hacks up a healthy plant. Removing large fan or shade leaves DOES NOT make plants more productive. This practice DOES NOT supply more light to smaller leaves and growing tips. Plants need all their leaves to produce the maximum amount of chlorophyll and food. Removing leaves slows chlorophyll production, stresses the plant, and stunts its growth. Stress is a growth inhibitor. Remove only dead leaves or leaves that are more than 50 percent damaged.

There are a few basic techniques to pruning marijuana, including:

Prune off the top of the plant below the first set or two of branches to drive hormones to lower branches. Pruning off more of the main stem will increase the effect.

Prune off the tip of plants lo diffuse hormones and make lower branches grow more.

Prune the tips of all branches except the main tip to make plants tall.

Remove lower branches that do not receive light. Plants will direct energy into buds.

Pruning off all lower branches makes inspecting irrigation fittings easy and diminishes problems associated with weak growth.

Remove spindly branches and growth that is not collecting light energy, including dead and dying leaves. Pruning lower branches concentrates auxins in upper branches which forces growth upwards. Cut lower branches off cleanly at the stem so no stub is left to rot and attract pests and diseases. If you must harvest a little smoke prematurely, removing a few lower branches will diminish the harvest the least.

Pruning out spindly branches and growth inside plants opens up the interior and provides more and better air circulation. It also allows light to reach deeper inside plants.

Not pruning has several advantages. Floral hormones are allowed to concentrate in tips of branches causing buds to grow stronger and denser. Unpruned plants are crammed into a small area. Crowded plants have less space to bush out laterally and tend to grow more upright. Clones are set into the flowering room after 1-30 days in the vegetative room. All the little clones are packed tightly together in three-gallon pots. Each one of the plants is taking up the minimum amount of space for the minimum amount of time to produce the maximum amount of marijuana. Light is much more intense, and the entire plant grows flower tops with few fan leaves.

No pruning was done in this room. Buds were so big in this room that plants were staked with bamboo sticks.

Pruned plants often seal themselves, but problems can still arise when there is an appealing opening for pests.

Most successful growers do not prune at all, especially if growing a short clone crop that is only two to three feet (61-91 cm) tall. Short clone crops require no pruning to increase light to bottom leaves or to alter their profile. "No pruning" is the easiest and most productive method when growing short crops.

Pinching back or pruning tops (branch tips) causes the two growing shoots just below the cut to grow stronger and bigger. This increases the number of top or main buds. Pruning tops also diffuses floral hormones, These hormones (auxins) prevent the lateral buds from growing very fast, All lower branches develop more rapidly when the terminal bud is removed. The further a branch is from hormones at the plant tip, the less effect the auxins have.

To pinch back a branch tip, simply snip it off below the last set or two of leaves. Pinching off tender growth with your fingers helps seal the wound and is often less damaging to plants than cutting. When the main stem is pinched back, side and lower growth is stimulated. When all the tops are pinched back, lower growth is encouraged. Continually pinching back, as when taking clones from a mother, causes many more little branches to form below the pruned tips. Eventually, the plant is transformed into a hedge-like shape. Most growers do not pinch plants back, because it diminishes the yield of prime, dense tops; but it may not affect the overall weight of dried smoke.

Supercropping is a form of pinching back or pruning branch tips. We are not sure who or when the term or buzzword was coined. We do know that there are several different versions of supercropping "invented" by innovative growers.

The main growing tips of this large patio plant were pruned off, which stimulated lower growth.

Supercropping can also incorporate FIM pruning which is explained below. It can be combined with bending, too. Some people go to the point of mutilating plants by breaking branches a few inches below main buds. Removing healthy leaves so that "budding sites get more light" is also practiced by some supercroppers. See "Stress" below for more information.

Floral hormones are concentrated in four main branches.

Pruning all the branches or removing more than 20 percent of the foliage in a short time frame stresses plants too much and diminishes harvest. But if taking clones, some growers effectively prune a mother down to stubby branches and let her recuperate for a month or longer.

Pruning too much over time may alter hormonal concentrations, causing spindly growth. This is often the case with mother plants that provide too many clones, The mother must rest and gain girth, because small, spindly branches root poorly.

Remove all but the four main branches. The meristem (central stem) is removed just

above the four lowest (main) branches. Removing the central leader concentrates the floral hormones in the four remaining branches. Fewer branches are stronger and bear a larger quantity of dense, heavy flower tops. Remove the stem above the four main branches; do not remove leaves on the main branches. Select plants with three sets of branch nodes about six weeks old, and pinch or prune out the last set of nodes so that two sets of branches remain. Move plants into the flowering room when they are about 12 inches tall. 'Skunk #1' and similarly robust bloomers should be set in the flowering room when about six to eight inches tall.

The FIM Technique was coined by an anonymous High Times reader from South Carolina in the July 2000 issue of the magazine. The technique has become legendary on, ever since the grower wrote; "this pruning technique could revolutionize indoor gardening." The South Carolina grower tried to pinch the tip of a plant and said "Fuck, 1 Missed!" when he did not remove the entire bud and coined the acronym FIM.

FIM Technique

The drawing on the left shows the traditional method to top a plant. The entire growing shoot just below the bud is removed. When the entire growing shoot is removed, the two buds located directly below the cut grow faster and stronger. The drawing in the center and the close-up on the right show the FIM pruning technique - the bottom ten percent of the bud remains intact. This is the key to FIM pruning. Many different flowering tops form as a result of this single pruning. According to FIM afficionados, terminal buds put on much more weight and are more dense.


Bending is similar to pruning, in that it alters the flow of hormones. Bending efficiently neutralizes the effect of the growth-inhibiting hormone. Bending is much easier on plants than pruning. To bend, lean a branch in the desired direction and tie it in place. Branches can take a lot of bending before they fold over or break. Even if a branch folds, tie it in place; if necessary, use a wooden splint. The stem will heal itself. Young, supple branches take bending much better than old, stiff ones. Bending branches horizontally will encourage the buds to grow vertically towards the light. Each bud will

turn into an impressive top, because they all receive more light A wooden planter box with a lattice trellis alongside makes a great anchor to tie bent plants to.

Wire ties, the kind used to close bread sacks, can be purchased at a nursery. Wire ties are either pre-cut or cut to length by the grower. Plastic-coated electronic and telephone cable wire also work well. They are fastened with a simple twist and stay rigid, leaving the stem breathing room. But if applied too tightly around a stem, the liquids cannot flow, and death could result.

Be gentle when bending, even though cannabis can take much abuse. Sometimes a crotch will separate or a branch will fold over, cutting off fluid flow. These mishaps are easily fixed with a small wooden splint snugly secured with wire ties or duct tape to support the split and broken stem.

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