Professional Cannabis Cultivation

11) Mothers


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Lesson Summary:

In this lesson, Cameron discusses what the professional grower needs to know about mother selection.


Lesson Transcript:

Hi guys. I’m Cameron, and today we’re going to be talking about mother plants.

The way that I think about my production schedule, and the way that I plan for the clones I’m going to take in order to achieve the number that I want in the flower side, let’s take an easy round number, let’s say we’re going to run with 1,000 plants in the flower room. To run with 1,000 plants in the flower room, if we have three vegetative phases and we’re going to have attrition throughout the life cycle, we probably want to start with 1,500 clones, we end up with 1,400 plants in veg one, we end up with 1,300 plants in veg two, we end up with 1,200 in veg three. Of those 1,200 I’m going to hold back say another one hundred, and we can still get rid of the worst hundred and then we’ve basically got the 1,000 and that’s what’s going to go out to the room.

Now to take it another step, let’s say the hundred that we hold back, we have the potential to get let’s say fifty clones from each one of those, so we don’t even really need all one hundred of those, but we need to be thinking about always creating enough padding in our system to consider the possibility of some sort of catastrophic problem, so baking padding into the system all the way through the production life cycle is one of the ways that we mitigate risk. Certainly we did it in prop, we do it in veg, and we also have to do it with our mother selection as well.

In terms of the production schedule, I like to think of things in two week increments. On the veg side we have propagation which generally two weeks, and veg one is just the first two-week increment outside of propagation, and then veg two is just the next two weeks. And depending on what our facility looks like, look if we’re going to go outdoor with these things we might veg these things for two months in a greenhouse. If it was a two-month veg in a greenhouse, we’d have propagation for two weeks and then we’d have veg one, two, three, and four. So really the sky’s the limit it sort of depends on what the external constraints are. If we’re going into a racked flower room, we might have a plant that has only gone through veg one and/or a veg two. It’s all sort of dependent on whatever your particular constraints, but again I think about the production schedule in terms of two-week increments.

So the way I think about mother plants and the sort of clones that they will provide to me, I think about things in sort of round numbers, so I’m looking at a mother that’s going to produce for me, fifty clones. To get that mother to give you fifty clones is probably going to take roughly four weeks from whatever our last veg phase is. So to go back to the example of three veg: veg one, veg two, and veg three, we’ve now got six weeks of vegetative life. Now we pull back our mothers, those mothers are going to veg for another 2-4 weeks, and they’re going to kick out roughly fifty clones.

So to get 1,000 plants in flower we need to start with 1,500. If we were thinking in blocks of fifty, we need twenty plants to get to 1000. We need another ten on that to get to the 1,500, so we’re talking about, what did we say? Twenty plus ten, we’re up to thirty, I mean maybe fifty mothers. Again, I’m trying to think of these in terms of round numbers so we’re probably, I said we could hold back one hundred, we’re probably only going to need fifty of those hundred.

Although I’m agnostic largely when it comes to media, I sort of defer to whatever the client wants or whatever my employer wants. If we’re going with the rockwool scenario that I prefer, we leave propagation and we go from a propagation cube into let’s say a six-inch rockwool block. Once we’ve gone through veg we would that six-inch rockwool block and stack it on either an eight-inch rockwool block or onto a rockwool slab. I would not advocate for mixing media, that is to say I would not take rockwool and put it in a pot with coco. We have different sort of drainage and other potential risks associated with that.

In terms of feeding mothers with regard to nutrient concentrations, I am generally maintaining the same EC or/or PPM level that I was feeding at when they left the last stage of veg. So again, if we are leaving veg three it’s somewhere around 800-1,000 PPM I’m probably maintaining something around 800-1,000 PPM. As that mother gets very big, very robust, I might bump it up a little bit i might try to go to 1,000, 1,100, maybe 1,200 PPM but definitely right in roughly the same pocket we were looking at on the veg side.

With regard to the life cycle of the mother, I wouldn’t keep a mother more than six months and generally I keep it less than 6 months. I would take one to two rounds of clones from that mother under the auspices that there’s going to be another set of that same genetic coming down the production pipeline that I would pull my next round of mothers from. And because I pick my mother’s based on the top ten percent instead of the bottom ten percent what I get is like the opposite of generational fade, so instead of fading downwards, they fade upward and so over successive generations we get more vigor, more robust growth as opposed to a fading and a degradation. It’s common to observe and experience fading in your genetics in commercial cultivation facilities because frequently the kind of control the you would need to really maintain genetics or enhance genetics over time, it’s not something that be controlled, there’s too many people involved, there’s too many hands, there’s too many cooks in the kitchen. In my experience when it was just me sort of working my own commercial facility all by myself, I was able to grow a particular strain for ten years and it actually improved over the ten years. It did not decline over the ten years. It became more robust, and I saw improved yields and improved quality over that time.

In the past I’ve gone into facilities and I’ve seen the kind of genetic fade that a lot of people have seen in their lives. And the real reason for this is that there was no control over the propagation process and the mother selection process. So frequently what will happen is cultivators will take their best ninety percent and run them out into the flower room and they’ll hold back their worst ten percent, and they will use that as their mother stock. It doesn’t take a genius to realize if you’re cloning from the worst of the lot as opposed to the best of the lot, in very short order your going to end up with a plant that has genetics that are fading.


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Course Notes:

Recommended Reading:
Good Mother Plant Nutrition – Necessary for Successful Cloning
How to Grow Cannabis 122: Genetics – Clone
“Why Successful Plant Cloning is Important” is locked Why Successful Plant Cloning is Important
Aeroponic Cloning Tips and Tricks


Suggested Products

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True North Seed Bank
Fiskars Premier Softgrip Micro-Tip Scissors
Rx Green Solutions – Life Cloning Solution
Grodan Stonewool Delta Starter Mini-Blocks


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