For an indoor gardener to have a perpetually successful garden, they must first become successful at cloning. The ability to successfully clone a plant enables a grower to continue using a variety of plant that, for one reason or another, has desirable attributes.
For example, if a tomato gardener finds one particular variety of tomato plant that produces abundant fruits with all the desired flavor qualities, the grower may want to clone the variety so an entire garden can be grown of that variety.
Although each garden is different and each plant variety may have slightly different needs, there is a general step-by-step process one can take to become familiar with the cloning process.
Selecting the Best Mother Plant
The first step a gardener must take in the cloning process is selecting a donor plant. Aside from having the desirable qualities that make the grower want to duplicate it, a donor plant should be a healthy plant free of stresses, diseases, pests and pathogens.
With traditional cloning, you end up with not only a genetic duplicate of the donor plant, but also any negative issues that were affecting the donor plant at the time of cloning.
In other words, when you clone a sick plant, chances are good the clones will be sick, too. A good rule of thumb is to closely examine a potential donor plant a few days prior to cloning for insect damage, molds or fungus, and check the overall health of the leaves.
Ideally, a donor plant is in the vegetative stage of growth. Donor plants reverted from the flowering state are acceptable and, in some cases, actually preferred.
It is also acceptable to take clones off a lower section of a plant as it enters the first stages of fruiting and flowering. Clones taken from a donor plant that is too far along in its fruiting or flowering stage will usually result in low success rates.
One way to increase cloning success is lessening the light intensity on the donor plant 24 hours prior to taking clones.
This can be done by lifting the lights farther from the plant canopy or by placing the donor plant in a low-lighted area. You are essentially allowing the plant a little rest and reducing the stress that can sometimes accompany rigorous growth under intense artificial lighting.
How to Take Perfect Plant Cuttings from a Mother Plant
Once the donor plant is selected, the grower can prepare to cut clones. Personal preference will play a part in the size of the cutting a grower will take.
When I’m taking my cuttings, I look for any shoot with at least 2 to 6 in. of stem that has a node within that 2 to 6 in. Different growers have different methods when it comes to the way they cut clones.
Some growers make the final cut underwater, first cutting the stem to remove from the donor plant and then, subsequently, making a cut underwater to avoid an air embolism. I never got into the whole underwater cutting thing.
I have always had high success rates by simply cutting the stem at a 45-degree angle, right at or right above a node. I prepare my cloning gel in advance so I can immediately dip the clone once the 45-degree angle cut has been made.
There are many different cloning gels and powders on the market and they all seem to do a pretty good job. In a recent experiment, I decided to try using honey as my cloning gel.
To my surprise, clones rooted just as fast with as high a rate of success as with a cloning gel. For the grower on a budget or big into organics, honey should be tried as a cloning gel.
The Best Medium for Plant Cuttings
Again, it becomes a matter of personal preference for the medium chosen. I have successfully rooted clones in stonewool, hydroton, soil, various soilless mixes, pumice, perlite, vermiculite and sand. My personal favorite is stonewool.
No matter what medium chosen, try to adjust the medium’s pH to slightly less than neutral. In other words, a slightly acidic solution should be run through the medium to bring the pH slightly below 7.
The medium used for cloning should be kept moist but not soaked. A well-aerated medium for cloning can make or break it once the initial rooting begins.
It is also a good idea to provide a small amount of food when clones begin to root. There are many different specialized cloning conditioners (rooting solutions) that will provide a small sustenance for plants with emerging roots.
A diluted bloom fertilizer (about one quarter of the regular dosage) can be used as a substitute in a pinch.
Growers who use an aeroponic cloner will not need to condition the medium for cloning. Once the clone is taken and the rooting gel has been applied, the clone can be placed in the machine.
I usually run the machine while I’m adding clones so that the first clones taken aren’t suspended in air during the entire cutting process.
Many growers use straight water in the clone machine, although I always prefer mixing a little vitamin B-1 and some rooting solution.
The biggest problem with clone machines is keeping the unit sterilized between each use. One solution is running the machine with a concentrated hydrogen peroxide solution between clone cycles.
Another solution is using a diluted bleach solution to clean the machine and the neoprene inserts. Just be sure to triple rinse any piece of equipment that was cleaned with bleach, ensuring all residual chemicals are removed.
Lighting Strength for Cuttings and Clones
Clones generally do not need intense lighting. A florescent lighting system is more than enough for a cloning tray or aeroponic clone machine.
There have been many debates over red versus blue light and how each affects rooting, but I have had equal success with all kinds of light spectrums. One thing is certain—a grower does not need intense light for successful cloning.
In fact, light energy that is too intense will hinder the process. Growers can get good results with an 18- or 24-hour lights-on period. I prefer a 24-hour lights-on period because it makes maintaining a consistent temperature easier.
Environmental Conditions for Clones
Successful cloning is largely determined by environmental conditions. As they are not yet established plants, clones require environmental conditions that differ from the other plants in an indoor garden.
To rectify this problem, many gardeners will create a specific room or area for clones where the environmental conditions can be kept in check. All indoor garden plants thrive in consistent environmental conditions and no plant illustrates this better than a clone.
Clones prefer temperatures between 75 and 85°F, with the ideal temperature around 78°F. A seedling heat mat may be the best tool to use to keep clones at a consistent temperature. For ultimate control, a thermostat can be connected to the heat mat and the desired temperature can be selected by the user.
Humidity is another environmental factor that affects clones. Generally speaking, clones prefer an environment with humidity of 90 to 100% for the initial days after being cut from the donor plant.
This high humidity is one of the factors that will stop the clone from completely wilting over because it is able to obtain some moisture from the surrounding air.
A propagation dome is a great way for growers to keep a microclimate around clones and maintain a high level of humidity and a consistent temperature.
Acclimation of Your New Clones
After the first few days, clones can slowly be acclimated to a lower humidity. This can easily be done with many of the propagation domes, which include ventilation ports that can be opened or closed and are available through local hydroponics retailers.
By slightly cracking the ports more and more each day, a grower can slowly acclimate clones to the ambient humidity. If using a make-shift dome or a dome without ventilation ports, the dome can simply be removed for increased periods of time each day until clones have become acclimated.
A good starting point would be 10 to 15 minutes the first day and then increased by that amount each day after. Clones can be acclimated to lower temperatures as well, but it is usually best to do this after the first signs of rooting have appeared.
Rooting Tips for New Clones
After seven to 10 days, clones usually begin to show roots. Some plant varieties take longer and some don’t take as long. Once clones are rooted and acclimated to the ambient humidity and temperature, they can be treated as vegetative plants.
Clones can be transplanted into the desired medium and fed a slightly diluted vegetative fertilizer. It is a good idea to acclimate freshly rooted
clones to the lighting system before placing them directly in intense light. A grower can raise the lights for a few days until the plants start to reach for it, and then incrementally lower the lights to the desired level.
Tissue Culture Cloning
A more scientific approach to cloning that has recently made headway in the hobbyist market is tissue culture cloning. Tissue culture allows gardeners to make clones from plant cells or tissue. Tissue culture cloning allows the gardener to grow a plant in a petri dish from the tiniest slice of plant tissue.
The biggest advantage of this process is that any pathogens, diseases or pests infecting the donor plant will not be transferred to clones.
Tissue culture also helps gardeners preserve rare and endangered species, or rescue embryos in distantly related cross-pollinated species.
The biggest disadvantage of tissue culture cloning is that it is an involved process that requires special equipment. For most hobbyists, standard cloning is a much more practical application.
In the end, cloning is a simple way any gardener can replicate the best qualities found in their indoor garden. Once indoor gardeners master the art of cloning, they have acquired the ability to perpetually produce their favorite plants.
This can open a whole new world of possibilities within their gardens and can certainly go a long way in maximizing their garden.
When the appropriate plants are selected and replicated, the garden’s attributes are intensified. This is because harvest after harvest the gardener will have the ability to reproduce the plants with the best-tasting fruit that grow the fastest and produce the most prolific yields.