Plants, like us humans, do not tolerate stress well. Vegetative propagation and transplanting are two of the most stressful times your plants will endure during their lifecycle. Limiting the amount of stress is ideal for the most fruitful growth. So, does a humidity dome limit the amount of stress and encourage abundant root growth in vegetative propagation?
After several rounds of testing and seeing results favoring one option over the other, we decided to elucidate the point by setting up a 14-day cloning cycle with two identical EZ-CLONE Classic Plant Cloning Systems. Using a variety of plants, we controlled for all other factors except for one: one system with a humidity dome and the control system without any covering. Confirming previous testing, not one of the cuttings performed better with the use of a humidity dome. The control systemâs cuttings exhibited more abundant root growth, longer roots with more developed secondary lateral growth and appeared to be less stressed, showing no signs of wilting. Moreover, the cuttings in the control system never wilted during their transplant into soil, unlike the cuttings that were propagated under a humidity dome.
When you take a cutting from a mother or donor plant, you are severing it from its life source. The absence of moisture being supplied to the cutting sends the cutting into a “fight or flight” scenario, a life or death decision as it tries to live on its own. It can choose the blue pill and continue itâs existence by propagating roots or has the option of the red pill, otherwise known as certain death. Increasing the level of humidity that surrounds the cutting with a humidity dome offers a layer of comfort and false protection, allowing the cuttings to still absorb their required moisture. Providing the cutting with all the moisture they require through a humid environment delays the response to sprout roots. When a cutting is sprouting roots, it is in search of moisture. The sooner you force your cuttings to seek out methods of survival on its own, the sooner it will recover from the stress of being sliced away from its mother.
Furthermore, the absence of a humidity dome delivers a double dose of shock and stress at once. I look at this as a two-for-one scenario. Once you’re already stressed, a little more isn’t going to kill you. By forcing the cutting to seek moisture on its own, the root structure will be forced to grow while the plant becomes acclimated to the open air. Think of this as a screening process: throwing your cuttings to the elements as they will not be living under a humidity dome their entire life. The sooner they become accustomed to the “real world”, the better off they will be. Survival of the fittest!
When you only deliver one stressor at a time to a cutting, you inevitably prolong the effects of each stressor. As soon as your cutting is getting over the stress of being clipped from its mother, you are shocking it again by transplanting it and removing the humidity dome. A cutting that has already coped with the stress of no humidity dome throughout the propagation process will be more ready for the outside world.
The use of a humidity dome during the traditional method of propagation is used to keep your medium wet. If the medium dries out, so will your cutting. But with aeroponic propagation, the proper ratio of air and water is already being delivered to the plant. Not only is the plant receiving enough moisture in an EZ-CLONE Classic System, but the moisture is being delivered to the portion of the plant that actually uptakes the moisture.
If you’re ready to take your cloning to the next level, remember to…Ditch the Dome!
Below, you can see three side-by-side comparisons of a 14 day cloning cycle with identical EZ-CLONE Classic 32 Plant Cloning Systems.
The control system (no humidity dome) as you probably guessed, are the cuttings on the right side of photos with more prolific root growth.