Cloning is the process of taking a cutting from your plant and getting that cutting to grow into a new, full-grown plant that is a genetically identical to the original.
Though it may sound intimidating, it's actually a relatively easy
process. Cloning simply requires some patience and understanding. In
this article we will break down the process step by step so you can also reap
the benefits of cloning.
· Propagation tray with grow plugs
· Clonex Cloning Solution
· Pruning shears
· Rubbing alcohol (to sterilize scalpel between use)
· Shotglass (to hold cloning solution)
· Cup of water (to keep clones in before transplanting)
· A mother plant to cut
Take all these and find a good place to sit for the cloning process. Remember to clean all your cutting tools with the rubbing alcohol beforehand. You do not want to start the cloning process with dirty tools. Doing so can introduce issues to your clones from the start. We are, in essence, preparing for surgery - it just happens to be on a plant.
Allow new plants to grow for a few weeks or months before you clone them. Once they’ve reached adequate size, use a sharp, clean blade (sterilized with rubbing alcohol) to cut a few stems about 4 or 5 inches long. At this point, you can use scissors because you will create a fresh cut above this line before the clone is placed in the growing medium. Cut from the bottom and middle of the plant first, as this is the area that will grow the fastest and give you the best bet in the cloning of your plant. Pluck off one or two sets of leaves, and remove any lateral buds that have formed. The goal here is to keep the plant from losing too much water during transpiration, focusing its energy on rooting instead.
To prevent an air bubble (embolism) from lodging in the stem where the cut is, place the cutting in a bowl of water until you are ready to transplant it into your cloning tray or cloning system. Make sure to always keep the tip of the cutting moist. Continue to get as many cuttings as you want/need for this cloning session.
Now that you have a a bowl filled with fresh cuttings, remove each cutting individually and create a fresh cut a 2-3 centimers above the original cut, just above or below the node. You want your cut to be at a 45° angle to expose as much surface are as possible. Do not use scissors to make the 45° cut as scissors have a crushing action when they cut, which can create compression cuts that can make it difficult for new roots to grow. You can accomplish an excellent cut if you use a mild slicing motion when you cut downward.
Immediately dip the freshly-cut cutting into your cloning gel (such as Clonex), and place it gently into your rooting plugs. Follow the directions for rooting solutions carefully - if you leave the cutting for too long in the gel it can “burn” the cut area. Never dip your clone directly into the container, always pour your cloning solution into a separate container to reduce the chance of contamination. Wipe off the excess rooting gel or powder for extremely sensitive plants.
There are many cloning trays that are available for clones, such as Root Riot. Many gardeners also prefer to use rockwool plugs. If you use these, make sure you presoak the plugs in pH 5.5 nutrient solution for a few hours. You can also use Europonic Rockwool Conditioner to make the process more efficient. Rockwool is spun volcanic rock, and some of the rock is limestone. There will be residual lime in the rockwool, and lime raises pH. Wetting the rockwool beforehand with a low pH solution will stabilize the pHand prevent upward swings.
If your air is dry you should keep the clones under a humidity dome. Keep the dome closed for the first 24-48 hours. During this time, check moisture and temperature frequently and mist cuttings morning and night with water. You can also add SuperThrive or Thrive Alive Green to help your clones overcome transplant shock, a few drops per gallon of water is all that is needed. Both are rich in thiamine (also known as vitamin B1) and natural growth hormones. In plants, B1 is produced in leaves and migrates down to the root zone, where it encourages root growth.
Place the tray under proper lighting, such as a T5 Fluorescent or Compact Florescent Lamp for 18 or 24 hours of light per day. After the first 24-48 hours passes, open the dome at least once a day to “air out”. Only open the dome for 15-30 seconds at a time. Always leave a small layer of water at the bottom of the tray, halfway filling up the grooves along the bottom. However you do not want to let the cubes sit in water. The idea is to keep the humidity levels high without over-saturating the plugs. Monitor the cubes throughout the week. Make sure they stay moist (but not soaked).
After a few days you may notice that some of the leaves are beginning to turn yellow; this is a natural process (however this doesn’t always occur). It also tells the gardener that rooting is about to begin. The yellowing will disappear once the roots have formed and are being fed a light nutrient solution.
After 7 to 10 days, inspect the bottom of the plugs by lifting the inner tray. If you see roots beginning to form, you can gently tug at the cutting to see if it’s ready for transplant. If you still do not see signs of roots by 10 days, gently tear apart the plug to see if the cutting has become soft and slimy. If so, toss it out along with its rooting medium. If the cutting isn’t soft and slimy but has white bumps just above the cut then it is about to root. Discard all cuttings that are beginning to rot; harmful organisms will spread easier in the machines.
Once the cutting has rooted introduce it to a ¼ strength nutrient solution (50-200 ppm). Keep the pH at around 6.0-6.3. Within a few weeks a strong rooting system should be established and clones should be ready to be transplanted to their regular growing area. In another month or so these plants will be ready to be parents themselves. Simply follow the same process as the first clones for each subsequent generation and it can be continued as long as you wish.
Clean the trays thoroughly between each cycle. Bacteria and fungi spores can grow in dirty wet trays, which can lead to damping off disease. Use a diluted 35% hydrogen peroxide solution and water to clean them off. Do not reuse rockwool cubes or oasis/peat plugs after they have been used throw them out and buy fresh ones.
And remember, cuttings are never guaranteed to have a 100% rooting success - all the gardener can do is help increase the chance of rooting.
Another way of cloning plants is by tissue culture, which works not with cuttings but with tiny pieces from the parent plant. Sterile agar jelly with plant hormones and lots of nutrients is needed. This makes tissue culture more expensive and difficult to do than taking cuttings.
Tissue culture involves the following steps: