CLONING PROCESS
I prefer rockwool over the alternative options. In my experience, there are options with less expense, but that comes with a price… Jiffy plugs, root riot, peat pots, etc. all work for rooting clones, but I have found that once they dry to a specific point - they become hydrophobic (resisting saturation, making them more of a maintenance challenge)
To begin, I grab my rockwool sheet (I prefer 2" AOK PLUGS/50 qty/sheet) I pop this rockwool into what they call a "CUT KIT TRAY" found at nearly every hydro store. The cut kit tray is a mesh tray inserted into a 10x20 propagation tray. This makes watering a removing the rockwool entirely from the tray very easy. The mesh also holds the rockwool slab up off the bottom of the tray, so once roots pop, they aren't pressed immediately into the bottom of the plastic tray and allowing them a greater level of oxygen. (The equivalent to root circling in plastic pots)
If planning on keeping the rooted cuts in the tray for an extended hold period: adding an inch thick layer of perlite, vermiculite, etc under the mesh insert and directly into 10x20 tray bottom is handy and keeps the roots happy over the long hold.
ROCKWOOL SOAK SOLUTION
20ml/gal CLONEX liquid solution/feed
(Add your favorite microbial inoculant)
1 TBSP/5gal EXTREME GARDENING MYKOS Water Soluble Powder
(Set the Ph of this solution to between 4.8-5.0Ph prior to adding microbial product)
The lime in the rockwool substrate drives this Ph up to around 6.0 immediately upon soaking.
(A trick taught to me by Kyle Kushman - thanks KK)
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Once the rockwool slab is soaked, it's time to pour off the excess water from the medium, thus pulling much needed oxygen into the slab. This can be done by holding the tray at an angle over a gallon pitcher, bucket, etc. Pour off between 50%-75% of the soak solution. Once the tray is set back onto a level surface, the water will distribute itself evenly throughout the slab. (They get heavy on the end that was "downhill" while pouring off excess.
Once the slab is prepped, we're ready to plug the cuts. For this portion, I have tried every cloning gel out there. (Synthetic or otherwise) For organic production, nothing beats Aloe Vera. I have many Aloe Vera plants around the outside of the house/workshop for household uses, but snipping a tip off a spear makes for a great organic rooting gel.
If you prefer the rooting products that contain IBA: I have not come across a more effective product than DIP N GROW. The product comes with a small plastic measuring container that is similar in size/shape to a double tall shot glass in a bar. Pour the DIP N GROW concentrate into the provided measuring cup up to the line marked CONCENTRATE LEVEL. Then, use RO/filtered water to bring the level up to the 5X line marker. (The solution can be diluted further, but make sure it isn't so deep that the stem gets exposed all the way up. You only want the part of the stem that will be inserted into the rockwool to be in the DIP N GROW solution. If you dipped the stem of the cutting halfway up for example, an inch or two of your stem above the rockwool will have unsightly white cuticle tissue forming where roots ultimately would attempt being produced.)
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Time to begin plugging your tray. Hopefully the selected cuttings are thick enough to not bend/break while being pushed into the rockwool. If one bends, it can be trimmed above the bend - provided it doesn't make the cutting too short to stick with the group.
Aim for the end of the stem to be pushed into the bottom 1/3rd of the cube. Now that we have poured off the excess solution, it's important the cuts not be plugged too shallow. This makes for poor footing/stability for the clone as well as the likeliness that the stem opening could be in the part of the rockwool that dries up first. This leads to wilted clones that will not root. If you drive the stem into that bottom 1/3rd of the cube, making sure to not push through the bottom, it's in the area of the cube that contains the nutrient solution and will keep the cutting hydrated throughout the rooting process. (Rockwool slabs will dry from the top down.)
When plugging: It’s crucial to make sure all of the tops of the cuttings are seeing daylight. What I do is place the stem down onto the rockwool where I want to plug it, and rotate each clone as needed to ensure the fan leaves of the cut I'm plugging don’t cover the new growth/top of any neighboring clones that are already plugged. Once plugged and in place, you can tuck larger fan leaves down under neighboring clones, ensuring all get adequate light. If clone tops are covered by fan leaves, they often times mush out and begin to rot.
Now time to apply the humidity dome
Carefully place the clean/sanitized dome over top of the tray, making sure to tuck in any fan leaves.
NEVER KEEP THE VENTS CLOSED on a fully plugged tray. I cannot stress that enough. If you just plugged 50 thick clones into a slab: there is more than enough humidity inside the dome to keep the clones hydrated for the rooting process. Most folks go wrong in this one little area. If you plugged a partial tray, (less than 25qty) you can place a small red party cup half full of water inside the tray with the clones. This will keep RH up and make up for the humidity the additional cuttings/rockwool would have contributed. I have found when folks keep the domes sealed up tight (and if and when a single clone wilts/dies…) it begins growing mold and contaminating all the good cuttings around it. Ever hear the old saying, "One bad apple spoils the whole bunch?" Keep the vents closed and find out first hand why that is!
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If the tray/dome are to sit in a regular room in the house, I aim to keep the dome in place (VENTS FULL OPEN) for the first 5-7 days. At that point, you can remove the dome and monitor the clones for any signs of wilting in the first hour or two after removing the dome. If you see any wilting, you can lightly mist the tray with (20ml/gal - Ph: 6.0) and replace the dome. Try the removal process again 24hrs later.
If the tray/dome are rooting in a controlled environment: the optimal parameters are:
80-83 degrees Fahrenheit with a RH (Relative humidity between 65%-70% f in the controlled environment - I aim to remove the domes on day 3 or 4. Same procedure: monitor them over the first hour or two, and if any wilting occurs, lightly foliar them and replace the humidity dome and try again in 24hrs.
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This method of removing domes before cuttings are fully rooted does a couple things.
• Prevents a single wilted clone from getting to grow that infamous grey mold and killing your other cuts.
• Hardens off clones faster. Who wants to wait 7-10 days to see their clones root just to watch them faint the day the domes come off?
When the clones complete the rooting process in this open air fashion: they are established and sturdy by the time roots show from the sides/bottoms of cubes. Let them clock in and get to work vs needing to be babied along for a couple/few extra days.
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The first watering they will receive depends on how soon you were able to remove domes and which environment they are kept in. There are many variables. Get to know the weight of the tray when it's first plugged. Then look for it to lighten up significantly before first watering occurs. (Same as you do when watering containers)
Once the tray is rooted, I typically like lifting the mesh insert and pouring about 500ml of feed solution into the bottom of 10x20 tray. Lower the mesh/rockwool back down into tray and the rockwool begins wicking up the solution. After a minute or so, lift the tray to see if it soaked up the majority of the feed. Add another 250ml or so if needed. It's ideal to keep a little excess solution in the 10x20 tray bottom which keeps any roots that have popped thru the bottom of rockwool happy and hydrated.
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Spraying/misting clones during the rooting process:
I have seen it recommended to mist the inside of the humidity dome daily. This is not necessary and often times leads to excess humidity allowing for mold/rot to occur. Trust that the humidity is high enough in there to keep them strong. 100% humidity is not required despite what High Times and Skunk magazine say… 65%-70% is perfect. Any more than that makes the clones dependent on that high humidity which is why fully rooted clones wilt when they hit the open air.
I do like foliar feeding after the domes come off. Either that Clonex solution (minus the microbes) works adequately. Your favorite veg feed at half strength works well also. The myth that clones need to be starved of nitrogen is also untrue, in my opinion.
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This process has been working like a charm for years… Not the only way to get roots, just what works for me.
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HAPPY ROOTING!