Air layering is a method of producing roots on a plant stem while the stem is still attached to the mother plant.
This bypasses all the hassle and expense of cloning equipment, eg aerocloners, cloning trays, misting tubs, foam pucks etc.
Almost everything from cannabis to lavender, tomato and jasmine (softwood and hardwood) can be cloned using this method and you don't have that anxious period of waiting to see if that tiny branch you cut off the main plant is actually going to live or not.
Once the roots have developed in 2 or 3 weeks, you can either pop it into a hydroponics tub with subdued lighting until the new root system is fully established, or pop it into a pot with an airy soil mix, eg perlite and coco peat 50/50 mix.
Step 1: Parts and Tools
You will need;
- Cloning gel or equivalent.
- Poppers a childs rubber toy, its turned inside out and placed on a hard surface, it then leaps off with a pop sound.
- Sharp blade for scraping the bark layers.
- Dremel tool with a small grinding stone to make the hole in the rubber popper.
- Vermiculite or sterile rooting medium of your choice, coco peat, moss, perlite etc.
- Medium size cable ties, mine where the 150mm long ones.
None of the nurseries in my town had cloning gel only the rooting powders, Seradix and Dynaroot, which is pretty much useless for air layering.
I've read that a decent clone gel substitute is KY jelly and rooting powder mixed in equal proportions, the resulting gel should be refrigerated if you're going to keep it for any length of time.
Step 2: The Popper Mod
I used a 5mm dia grinding stone to make the hole in the larger poppers with the dremel set to a 5 speed ie halfway.
I find it easier to light nick the 2 spots on one half to get the holes opposite each other.
Wear safety glasses, (gloves if you like) theres lots of tiny pieces of rubber flying around but if the dremel catches on the rubber and flings the ball away it might be headed for your eyes.
On the smaller popper I used the standard dremel 3.2mm drill bit seeing as I didnt have any smaller grinding stones.
Do NOT wear gloves, if the drill bit catches and shoots the ball apart you'll be left squeezing a drill bit and the gloves will only force your fingers harder onto the spinning bit, extreme caution is needed if using the bit method, the grinding stone will give you a bit of a burn and you'll lose a few layers of skin, the drill bit will make you cry and leave your fingers in a mess.
A slightly safer way if using the drill bit method is to wrap a strip of emery cloth (100 grit) around the popper ball and then hold the two ends, similar to the oil filter strap wrenches.
I originally tried using a small 30ml dropper bottle, with a cut down one side to hinge open, but this wasnt what I wanted seeing as the top had to be cut off and that left a large opening.
Next up was a ping pong ball which didnt cable tie well and the 2 halves had to be taped for alignment.
Finally I happened across poppers, a soft rubber half ball with an inner lip to hold rooting medium, easy alignment and it cable tied well, the rest, as they say, is history.
Step 3: The Plan
I had a rigoletto tomato passing the 6ft high mark with feeble fruit, time for a cut & clone.
- Select a suitable site above a node so that the popper doesn’t slide down.
- Measure up the area to be scraped for the clone gel.
- Scrape the out bark/layer.
- Apply the clone gel.
- Fill the 2 poppers to the brim with vermiculite and soak with water.
- Slap the 2 halves around the stem and cable tie together... done.
I also air layered a smaller site with the smaller size poppers just to get an idea of how effective the smaller size poppers would be.
It would be advisable to inject water every 2nd day with a syringe, I figure roots will appear much quicker when the medium is dripping wet as opposed to slightly damp.
I also removed all the flower/future fruit sites so that the plant can focus more on root growth. Once it has rooted then there will be less strain on the newly formed roots without fruit attached to the stem.
Step 4: Finally the Wait
I'm confident that the clone sites will sprout roots,however if it doesn't work at least you'll have some cool headphones for your Minions.
I also layered a French lavender branch seeing as I've had no success trying to root some.
Zzzzz 2 weeks later...
I had mixed success with no roots showing on the larger branch and also nothing on the 1 lavender twig that I did, however it could be merely my implementation of the procedure and not the actual procedure itself.
The lavender twig had lots of ants inside the popper and it seemed to have dried out so presumably they were taking the water as well.
I omitted to slice 1/3 of the way through the branch and prop it open with a toothpick, which is a step in the general layering process. I figured it would weaken the soft tomato branches unnecessarily and would require some tricky splints.
Working gently because of the new delicate roots, I cut off the flowers which would burden the young root system and plopped it into a coco peat/vermiculite mix.
Another 2 weeks, ie 03.11.2015
I've been meaning to water the main branch every day but have been busy with other projects, so I decided to cut and plant the main branch seeing as it was growing higher than the gutter line.
On opening the popper, the roots had filled up all available space and had started trying to exit in their search for water.