What is a Good Soil Mix for Cannabis Seedlings?

[Amnesia]

I won't be starting any seedlings for a few months, so now is the time to plan. I believe the initial soil I've used may be to blame for my slow plant growth problem during the plant's early life. I suspect it is because the seedlings haven't been rooting well. So, I'm seeking suggestions for organic soil growing.

As Mary Poppins said, "Well begun is half done!"

 

[Amnesia]

I think your making it more complicated than need be.

A thought experiment can seem so. The advantage is that they don't use any material resources.

I haven't had many seeds fail to pop or grow once they pop.

This isn't about success. It's about optimization. I'm following this path because I have seen almost no consideration of how to optimize the seedling stage.

I use the spring water they soak in to saturate then squeeze out a small piece of folded paper towel. same on top....no standing water...in a sealed small plastic 2 oz cup for each strain or seed. In a warm location 2 days later there are tails......

That's the sprout stage and doesn't apply to the seedling stage I'm discussing.

I saturate a solo cup full of promix......no additives.......once the cup is saturated it will be 1/2 full of wet soil....poke a hole, drop in the seedling, tap in place, head above or at soil level, put in warm location off the bright lights.....plant grows...once it has leaves it can get moved closer and closer to the light until its developed enough to handle it all.......I'm 100% if it pops it grows....just straight Promix HP, BX, Sunshine mix, Greenworld Vpw30, .

Okay.

They're good for almost 3 weeks with just water before they need a light feed to start.

Perhaps one way to think of the end of the seedling stage is when feeding begins.

 

[Amnesia]

Its a given that the cups have aeration but they're only in there 2-3 weeks depending on the size of the solo cups and it makes them easy to transplant out of and monitor watering needs

Is it a given? The sides of plastic cups don't allow aeration and thus don't enable oxygenation from the sides. I'm referring to @Shaded's post.

The seedling stage may be only 2 to 3 weeks, but I question whether that means it is unimportant. Basically, I'm wondering what a seedling might benefit from that isn't provided in a typical soil mix that is mostly intended for the vegetation and reproduction stages. Maybe there's no difference. Maybe there is. So far, which is true hasn't been determined to my satisfaction.

For example: Do we know whether adding a small amount of rock dust, like Azomite, would be beneficial for a seedling soil? My answer as of now is that I don't know.

 

[Amnesia]

I won't be able to respond for a while, so don't think I'm ignoring the thread. I am having a brain MRI this afternoon and I don't like those.

 

[Pipecarver]

Is it a given? I understand the advantage of smooth sides. I don't use solo cups. I have been using plastic cups designed for seedlings (according to the seller). The sides are flexible, allowing manipulation of the soil to make it slide out easier. The sides of plastic cups don't allow aeration and thus don't enable oxygenation from the sides. I'm referring to @Shaded's post.

The seedling stage may be only 2 to 3 weeks, but I question whether that means it is unimportant. Basically, I'm wondering what a seedling might benefit from that isn't provided in a typical soil mix intended mostly for the vegetation and reproduction stages. Maybe there's no difference. Maybe there is. So far, which is true hasn't been determined to my satisfaction.

For example: Do we know whether adding a small amount of rock dust, like Azomite, would be beneficial for a seedling soil? My answer as of now is that I don't know.

It might indeed, I had 4 sprouts in solo cups, 2 I transplanted into 3/4 gal pots and I ran out of soil. The next 2 after I got soil I added azomite, Gypsom and Worm castings to my mix and transplanted the last 2 plants into larger pots with that new mix......in 2 days I noticed a swelling of the stalk at the soil level on the 2 in the new mix. I had pics on the farm....2 with the new mix came out of the soil like a cone and continued to enlarge. I just looked at them and although I've stunted them some in the small 3/4 gal pots I can still easily see which is which and the larger base on the plants comes from the new mix.

 

[Rootsruler]

Limiting the discussion to the seed to solo stage I would say that 2 things need to be defined first. What is considered the optimal nutrient balance for that stage of the life of the plant and where does the seedling stop self nourishment and begin to feed itself primarily through its root system? After first node? Once Cotyledons drop? After first set of leaves?

I also see it in 2 stages. Seedling stage where the seed sprouts it's tap root and is self nourishing and early veg where roots and leaves take over the intake of nutrient ions.

 

[Pipecarver]

Limiting the discussion to the seed to solo stage I would say that 2 things need to be defined first. What is considered the optimal nutrient balance for that stage of the life of the plant and where does the seedling stop self nourishment and begin to feed itself primarily through its root system? After first node? Once Cotyledons drop? After first set of leaves?

I also see it in 2 stages. Seedling stage where the seed sprouts it's tap root and is self nourishing and early veg where roots and leaves take over the intake of nutrient ions.

I saw a YT vid with 2 white coated pro's talking about the enzymes the seeds release when they crack is vital to their initial growth so putting 1 seed in a gal of water won't help the seed where as in a smaller amount of water its beneficial to soak in. I concluded that more is better, more seeds = more vital enzymes to nourish the seeds I want to grow. So I've made a supper juice at times where I've dropped 20+ old hermied seeds into a cup of water then in the morning dump the seeds and use the water to pop the seeds I wanted to pop.....lol...sure they popped and grew but who's to say they wouldn't have any ways...

 

[Shaded]

Thanks.


I'm sure this is the direction I'm headed, and you've provided me with a solid foundation for further thought. So far, I've mostly been thinking about rooting capability. I haven't mentioned transpiration yet, and that factors into what is in this theoretical first soil.

We see solo cups commonly recommended, which, with their plastic sides, is contrary to your recommendation for fabric or air pots. I agree that oxygenation would be an important consideration for a first soil. Perhaps perforations on the sides of a solo cup would be helpful.


I understand. I question the practice of using a low pH substance (peat) and then adding a high pH substance (lime) to adjust the pH. What benefits does peat provide that warrants the addition of lime?

Every growing medium will have their pros and cons. I am by no means a soil or medium manufacturer so I cannot argue any of the finer details when it comes to soil compositions. All I can say is what has worked well for me and why I believe so, and what research/articles I find beneficial with any sort of questions or concerns I have with medium of choice. Peat has a high base pH, that could be argued as one of the cons(or pros depending on what you are growing) but companies like ProMix have done their due diligence to ensure their product comes with some other goodies and self buffering capabilities. A simple google search will show you a compiled list of pros and cons between each growing medium. I couldn't be bothered to water coco daily or multiple times a day, so peat is my choice hands down.

I personally have found the best success with organic dry amendments while using peat based mediums. If I was to switch to synthetic nutrients I would most likely be going coco or pure hydro. And yep poking holes in the side that would definitely work! Or take some of @Bandit420 idea and use perforated plastic cups and then line them with newspaper or coffee filter?

I feel like a lot of these questions you could def answer yourself by running some small sample sizes. I mean most of the things I do as habit now were developed through trail and error. Eliminate as many variables as you can and start with a good baseline - get some results and see what needs to be changed or improved. For example you could start 8 seedlings and run some control groups - A, B, C, and D. Give A nothing but water. Give B water and Azomite. Give C water, Azomite, and Gypsum. Give D water, Azomite, Gypsum, and Epsom. You can also run these control groups for different styles of pots or growing mediums that you want to compare. That's how I treated Gaia Green when I first started using it. I just ran some plants with nothing but the 444 or 284 and watched to see what they needed or see what deficiencies popped up.

The final note I will leave on is this: I firmly believe that growing is an art. There are many different styles of that art. It takes time to learn and master the finer intricacies of that specific art style. My advice to you is to pick and choose a style that you like that fits your needs and then work on mastering that style.

 

[stonemason]

I use 1/3 good compost1/3peat 1/3 perlite for seedlings. Mabey a touch less perlite. Rice hulls works too instead of perlite. I throw a couple handfulls of wood ash in each bucket of peat to help with its acidity.

 

[stonemason]

Keep them hot and humid.

 

[Amnesia]

It might indeed, I had 4 sprouts in solo cups, 2 I transplanted into 3/4 gal pots and I ran out of soil. The next 2 after I got soil I added azomite, Gypsom and Worm castings to my mix and transplanted the last 2 plants into larger pots with that new mix......in 2 days I noticed a swelling of the stalk at the soil level on the 2 in the new mix. I had pics on the farm....2 with the new mix came out of the soil like a cone and continued to enlarge. I just looked at them and although I've stunted them some in the small 3/4 gal pots I can still easily see which is which and the larger base on the plants comes from the new mix.

Hmmm... Well... The subject of the "Is it a give?" post had to do with aeration and oxygenation. That said, adding Azomite, Gypsom and worm castings is sure to help. I'm not sure they were still seedlings at that point, though. At least, not within the working definition I'm trying to establish.

 

[Amnesia]

Limiting the discussion to the seed to solo stage I would say that 2 things need to be defined first. What is considered the optimal nutrient balance for that stage of the life of the plant and where does the seedling stop self nourishment and begin to feed itself primarily through its root system? After first node? Once Cotyledons drop? After first set of leaves?

The first thing to define would be the seedling stage itself. I have attempted to do so, if only for the sake of discussion.

Before discussing nutrient balances, we need to define nutrients. Would rock dust, magnesium sulfate and/or calcium sulfate be nutrients? They probably are, but they're not in the same category as nitrogen, phosphorus or potassium. You're right, though, finding the right balance is an important part of creating a soil mixture. Continuing... Would a root growth stimulant be a nutrient? I think most would say not, yet it might be a useful addition to a seedling soil mix.

We routinely make decisions about when a plant transitions from self-nourishment to nourishing itself from its roots. It's the time when we decide to transplant to a larger pot. Apparently, there's a reasonable guessing involved. So, instead of attempting to precisely assess that transition moment in a plant's life, we could just call it the time when we transplant to nutrient-enriched soil. It may not be as accurate, but it is objectively definable.

I also see it in 2 stages. Seedling stage where the seed sprouts it's tap root and is self nourishing and early veg where roots and leaves take over the intake of nutrient ions.

I see the sprout as separate from the seedling stage. So do authors I've found out there in cyberspace. Opinions do vary, though. Here's are six-stages I found:

1. Sprout
2. Seedling
3. Vegetative *
4. Budding
5. Flowering
6. Ripening

* We also tend to speak of early vegetation as somewhat distinct stage.

 

[Amnesia]

I saw a YT vid with 2 white coated pro's talking about the enzymes the seeds release when they crack is vital to their initial growth so putting 1 seed in a gal of water won't help the seed where as in a smaller amount of water its beneficial to soak in. I concluded that more is better, more seeds = more vital enzymes to nourish the seeds I want to grow. So I've made a supper juice at times where I've dropped 20+ old hermied seeds into a cup of water then in the morning dump the seeds and use the water to pop the seeds I wanted to pop.....lol...sure they popped and grew but who's to say they wouldn't have any ways...

I recall seeing something about that, too. That's about sprouting, though, and I've been trying to separate from the discussion about seedling soil. The soil I'm trying to discuss becomes involved after sprouting has occurred.

 

[Rootsruler]

The first thing to define would be the seedling stage itself. I have attempted to do so, if only for the sake of discussion.

I would define seedling as the period where the seed is self feeding.

Before discussing nutrient balances, we need to define nutrients. Would rock dust, magnesium sulfate and/or calcium sulfate be nutrients? They probably are, but they're not in the same category as nitrogen, phosphorus or potassium. You're right, though, finding the right balance is an important part of creating a soil mixture. Continuing... Would a root growth stimulant be a nutrient? I think most would say not, yet it might be a useful addition to a seedling soil mix.

I would define nutrient as anything that is metabolized by the plant at that period that directly or indirectly accounts for plant growth. I would label things like rock dust as precursors as it has a plethora of minerals so I categorize it more as a soil conditioner than a nutrient. Magnesium/Calcium I would label as nutrients even though they start out as minerals and are directly involved in cationic transport.

Maybe a better way to categorize it is to not call them nutrients so much as a nutrient package. Minerals help some nutrients break down faster or help combine into a different type of nutrient ion. Certainly not nutrients but essential in the delivery of those macros. Same with stimulants. Not nutrients per se but certainly part of the package.

We routinely make decisions about when a plant transitions from self-nourishment to nourishing itself from its roots. It's the time when we decide to transplant to a larger pot. Apparently, there's a reasonable guessing involved. So, instead of attempting to precisely assess that transition moment in a plant's life, we could just call it the time when we transplant to nutrient-enriched soil. It may not be as accurate, but it is objectively definable.

I see the sprout as separate from the seedling stage. So do authors I've found out there in cyberspace. Opinions do vary, though. Here's are six-stages I found:

1. Sprout
2. Seedling
3. Vegetative *
4. Budding
5. Flowering
6. Ripening

* We also tend to speak of early vegetation as somewhat distinct stage.

I would tend to agree but technically vegetative would be defined as the moment the tap root sprouts. The sprout and seedling stages are definitions we've made up to be able to differentiate between those sub stages of vegetative.

One of the reasons we need to define when the seed leaves self feeding is to define when we've left the vegetative sub categories and have moved into primary vegetative state. The scope of your inquiry seems to be on what soil should sprouts be introduced to to be able to optimally thrive before it gets to the primary vegetative state. Once the seed has hit PVS we're now outside of the scope of your inquiry. The other issue in discussing this is that most of those stages blend into one another so there's no real way to define this period as this and that period as that. Sprout? I can define as the moment the tap root breaks the seed husk but I could also define it as a seedling because, technically, that's what it is. Seedling you could generally define as a sprout with an extended tap root going into the PVS. I could argue that all of these are wrong and that the moment the seed hull cracks we're in vegetative.

 

[Amnesia]

Every growing medium will have their pros and cons. I am by no means a soil or medium manufacturer so I cannot argue any of the finer details when it comes to soil compositions. All I can say is what has worked well for me and why I believe so, and what research/articles I find beneficial with any sort of questions or concerns I have with medium of choice. Peat has a high base pH, that could be argued as one of the cons(or pros depending on what you are growing) but companies like ProMix have done their due diligence to ensure their product comes with some other goodies and self buffering capabilities. A simple google search will show you a compiled list of pros and cons between each growing medium. I couldn't be bothered to water coco daily or multiple times a day, so peat is my choice hands down.

Are we comfortable with companies doing due diligence? I, for one, am not.

There may be growing media that have more pros than cons. We should acknowledge that companies seek to expand their market share, and that could well include making products targeted to a wide range of plant types. Do any specifically target cannabis? I'd like to know if there are. Then again, discussion of growing media may be in a realm beyond seedling soil. Most of the growing occurs during the vegetation stage. Some companies do sell seedling soil, but the few I've tried so far have been disappointing.

Peat has a low pH, typically about 5.5 and it can be lower still. Here's something thought-provokingly detrimental I found about peat:

Peat moss was used for years as an additive for soil mixes, because it absorbs and retains water and nutrients, prevents soil compaction, it's sterile, and it's acidic (great for acid-loving plants). However, it has a major downside: peat moss is a non-renewable resource, and it best serves our planet remaining in peat bogs to combat climate change. Use alternatives in place of peat moss, such as compost, coconut coir (coconut fibers), pine bark, PittMoss (recycled paper pulp), and worm castings.

Source: https://www.thespruce.com/make-diy-seed-starting-mix-3016715

You make a good point about the inconvenience of having to water daily. There are, however, alternatives to using peat to manage soil moisture, as mentioned in the quote from The Spruce. We can add perlite and vermiculite to that list.

I personally have found the best success with organic dry amendments while using peat based mediums. If I was to switch to synthetic nutrients I would most likely be going coco or pure hydro. And yep poking holes in the side that would definitely work! Or take some of @Bandit420 idea and use perforated plastic cups and then line them with newspaper or coffee filter?

I appreciate the successes you've had. I have been happily applying your recommendations to my growing pursuits. I am looking forward to my first harvest using your method in late July.

I might try perforating plastic cups. I don't like using plastic because even a good soil mix can dry too slowly. I mostly use plastic because it works so well when transplanting.

I feel like a lot of these questions you could def answer yourself by running some small sample sizes. I mean most of the things I do as habit now were developed through trail and error. Eliminate as many variables as you can and start with a good baseline - get some results and see what needs to be changed or improved. For example you could start 8 seedlings and run some control groups - A, B, C, and D. Give A nothing but water. Give B water and Azomite. Give C water, Azomite, and Gypsum. Give D water, Azomite, Gypsum, and Epsom. You can also run these control groups for different styles of pots or growing mediums that you want to compare. That's how I treated Gaia Green when I first started using it. I just ran some plants with nothing but the 444 or 284 and watched to see what they needed or see what deficiencies popped up.

I mentioned earlier in the thread that I currently don't have the capacity to test samples. I have two tents and both will be full for at least two months. I also don't have access to seeds for experimentation--not at about $10 each. Being somewhat frugal in nature, I try to grow every seed to harvest.

You do seem to understand my interests here, though. I am wondering about the addition of such amendments as Azomite or Great White. Thanks for understanding what I'm trying to do.

The final note I will leave on is this: I firmly believe that growing is an art. There are many different styles of that art. It takes time to learn and master the finer intricacies of that specific art style. My advice to you is to pick and choose a style that you like that fits your needs and then work on mastering that style.

To me, growing cannabis is both an art and a science. It is to you, too, because you acknowledged the science of it when you recommended using a scientific method for assessing different soil mixtures and outcomes.

I realized during my first grow that I needed to choose my own growing style and I am pursuing it, with thanks to you. In this thread, however, I am not asking for holistic advice regarding the entirety of the growing experience. I am trying to focus on one specific aspect of growing--the possibility of creating an optimal soil mix for seedlings.

 

[Amnesia]

I would define seedling as the period where the seed is self feeding.

I agree, in principle. In practice, I see two problems. One is that probably isn't a specific point in time, but rather a gradual change. The other problem is the lack of a way to know when it has occurred. The moment of transplant to a soil with the nutrients the plant needs may not be precise, but it is both specific and observable.

I would define nutrient as anything that is metabolized by the plant at that period that directly or indirectly accounts for plant growth. I would label things like rock dust as precursors as it has a plethora of minerals so I categorize it more as a soil conditioner than a nutrient. Magnesium/Calcium I would label as nutrients even though they start out as minerals and are directly involved in cationic transport.

Good! I like those definitions. Thank you!

Maybe a better way to categorize it is to not call them nutrients so much as a nutrient package. Minerals help some nutrients break down faster or help combine into a different type of nutrient ion. Certainly not nutrients but essential in the delivery of those macros. Same with stimulants. Not nutrients per se but certainly part of the package.

Okay. I'm with you on that, too.

I would tend to agree but technically vegetative would be defined as the moment the tap root sprouts. The sprout and seedling stages are definitions we've made up to be able to differentiate between those sub stages of vegetative.

Many sources distinguish between the sprout and subsequent stages of a plant's life. Making a distinction is purposeful here because the discussion pertains to the development of specialized seedling soil. Here, I'm assuming most growers sprout their seeds without soil, even though I know some growers plant seeds directly in soil. I'm not sure the difference matters, though. What is pertinant is that first soil that is used up to the point of the first transplant.

One of the reasons we need to define when the seed leaves self feeding is to define when we've left the vegetative sub categories and have moved into primary vegetative state. The scope of your inquiry seems to be on what soil should sprouts be introduced to to be able to optimally thrive before it gets to the primary vegetative state. Once the seed has hit PVS we're now outside of the scope of your inquiry.

True.

The other issue in discussing this is that most of those stages blend into one another so there's no real way to define this period as this and that period as that. Sprout? I can define as the moment the tap root breaks the seed husk but I could also define it as a seedling because, technically, that's what it is. Seedling you could generally define as a sprout with an extended tap root going into the PVS. I could argue that all of these are wrong and that the moment the seed hull cracks we're in vegetative.

Our inability to agree on definitions for the words we use certainly presents a challenge. It's odd that we know what it is, but we lack an agreed-upon name for it. It is only what it is. Whether the plant is a sprout, a seedling or vegetating, that first soil is still that first soil.

“What's in a name? That which we call a rose, by any other word would smell as sweet.”​

 

[Shaded]

A lot to decompress I will come back! The optimal growing medium is no growing medium at all us soil peasants live with that fact and we just do the best we can to emulate hydros capacity.

 

[Amnesia]

A lot to decompress I will come back! The optimal growing medium is no growing medium at all us soil peasants live with that fact and we just do the best we can to emulate hydros capacity.

Thanks. I appreciate that! I doubt I'll ever do hydro. It's not my style.

 

[Amnesia]

When I began this thread, I didn't expect it to be complex. I thought it would mostly be a matter of considering each of the growth factors and exploring how to optimize a soil mixture for each of those factors for young plants, that is, during the period beginning when a plant is first placed in soil and ending when it is transplanted to its next, nutrient-enriched soil. The benefit being to establish favorable growth patterns early in the plant's life.

On page one of this thread, I proposed a soil mix recipe as a starting point for conversation. I hoped it would be refined by the recommendations of experienced soil growers, for the benefit of all soil growers. @Rootsruler was almost correct about my intentions when he wrote "The scope of your inquiry seems to be on what soil should sprouts be introduced to, to be able to optimally thrive before it gets to the primary vegetative state." I would certainly want the young plant to thrive before the primary vegetative state, but, more importantly, I would want it to be well prepared to thrive during that state and beyond, all the way to harvest.

I think of a plant's life, when considered as a complete process, as an increasing rate of vitality up to the point the plant begins its reproductive stage. In the beginning, the plant needs little and can tolerate little of the external growth factors. Thus, at first, as a seed, it only needs moisture and warmth. As it grows, it needs and tolerates increasing amounts of other factors, including light, water and nutrients. Thus, my approach for creation of our plant's first soil mix has been to focus on the physical properties (texture, structure, density, porosity, consistency, etc.) and biological properties (the favorable microorganisms in the soil). Thus, the goal is to nurture the young plant and prepare it for its subsequent soil environments.

 

[Rootsruler]

Yes. Seedling preparation HAS to be done with later growth stages in mind. I will refer back to my "package" remark.

Each stage of early growth has its particular needs. Sprout doesn't need nutrition in the soil. It has its own but once it shoots roots then nutrition becomes a factor. So do we provide "hot" soil for the anticipated roots or do we start with a benign mix and raise the nutrient level in the soil as we Up pot? Up potting has to also be considered as part of this as the grower can manipulate the nutrition level in the soil the up pot contains. If I know that I'm up potting from solo to gallon I can use low nute soil in the solo and hotter in the gallon. This is why thresholds need to be defined if we're going to talk about what is the best soil for sprouts.

If I had to give a general answer I would say MOST basic potting mixes that are targeted with cannabis in mind should be fine and have all the physical properties needed but if we're trying to zero in on what is optimal then I would say coco in the solo as coco has negligible nutrition and a hotter basic mix like Roots Organic Original for the up pot to gallon. The nutrition in ROO has enough for around 3 weeks of solid nutrition before we might encounter any deficiencies so not too hot like, say FFOF, but certainly enough to provide what the plant needs at that growth stage and not burn the new roots. At that point you can decide how hot a soil mix you want to up pot to for flower that will satisfy the length of time the flower phase will take if you are trying to go seed to harvest without any added amendments.

 

[Bandit420]

I'll play
Ok so I consider there to be 7 stages of the plant's life.
germination
seedling ( a fragile spout, soft stalk, fresh cotyledons, 1-3 pointer leaves)
young veg (stalk begins to firm up, 5 point leaves, nodes are still balanced)
mature veg (when nodes begin to alternate, 7 point + leaves)
preflower (When plant has been switched to flower but before pistils show)
flower
ripening

For germination thru mature veg I keep it very simple and use a one size fits all soil and it's either Roots Original, Roots 707, or Roots Greenfields.
When plant is young it gets plain water. As it climbs thru each stage, it's fed liquid fertilizer with increasing amounts and frequency of feedings.
In addition, I only use RO water, no pH adjusting, and my liquid ferts is just liquid fish and seaweed at no more than 1/2 strength of bottle instructions

I also agree with Shaded in that these are questions best answered by the grower running small experiments within the grow and finding which performs best. This is exactly how I arrived at the point I am today in regards to which soils I use and why I use them. They're excellent for me but may not be right for the next grower.
If there was a stand alone product head and shoulders above all others and great for every grower, we'd probably all be using it but variables open the door for options, some better than others depending on application

 

[Amnesia]

Seedling preparation HAS to be done with later growth stages in mind.

I'd describe that as an assumption, not a fact. Sure, what happens next is important, but widening the focus obfuscates the task. Does it really matter what type of nutrients will be used in the next pot? Or does it only matter that the plant is healthy and well-prepared for whatever happens to it next?

I understand the desire to expand the discussion to later stages. That's where the fun is. It's just not what I'm wanting from this thread. I don't want to go into what growers should or could do after the transplant to the next pot. I am rather certain that we never would or could find the perfect-for-everyone, first-pot soil. We might, however, find a recipe that other soil growers could adapt to their growing style.

Sprout doesn't need nutrition in the soil.

That has been acknowledged. We don't need to restate that which has been accepted as axiomatic. Perhaps we can also accept that there are factors other than nutrition that affect a plant's health and well-being during its time in its first pot. What about the physical and biological properties of the soil that I described in post #48? We know that root development is intense during the period in question. Why is that? If it's important, what does the plant need to root well? What do those roots (and the plant as a whole, of course) need from the soil other than nutrition?

"Cultivate the root; the leaves and branches will take care of themselves." ~ Confucius​

If I had to give a general answer...

You don't have to do so. There are many general answers. I seek specifics. I'm trying to take this discussion to a level or two above it being a newbie question. I'm hoping to explore the science of early root development. I suspect I didn't present my intent well from the beginning, so I apologize for that. Then again, sometimes it takes a thread a while to filter down to its core purpose. I'll try to refocus the discussion to be more specific.

 

[Amnesia]

I'll play

Thanks.

Ok so I consider there to be 7 stages of the plant's life.
germination
seedling ( a fragile spout, soft stalk, fresh cotyledons, 1-3 pointer leaves)
young veg (stalk begins to firm up, 5 point leaves, nodes are still balanced)
mature veg (when nodes begin to alternate, 7 point + leaves)
preflower (When plant has been switched to flower but before pistils show)
flower
ripening

That's a good set of stages. I have seen other models, though. Here's a less-specific four-stage model from Leafly:

1. Germination (3-10 days)
2. Seedling (2-3 weeks)
3. Vegetative (3-16 weeks)
4. Flowering (8-11 weeks)

The focus here is on the soil used during Leafly's stage 2, which for many of us is the time the plant is in a solo cup. During this time, a plant is growing its first roots in its first soil.

I also agree with Shaded in that these are questions best answered by the grower running small experiments within the grow and finding which performs best. This is exactly how I arrived at the point I am today in regards to which soils I use and why I use them. They're excellent for me but may not be right for the next grower.

I also agree with @Shaded. Experimentation done independently is certainly an option. But if that's the only answer, why do we have a forum?

Experimentation must wait. I'll soon have both my tents in flowering mode and members of the household don't want the tents running during the hot months. That means I won't start new plants till fall.

If there was a stand alone product head and shoulders above all others and great for every grower, we'd probably all be using it but variables open the door for options, some better than others depending on application

You're right. If there were such a product, we'd be using it. But there isn't. That's why I endeavored to find one of our own--or close to it. For that, we need to understand what a plant needs during its first few weeks of growth. We have established that that is not nutrition. What, then, remains to be discovered?

 

[Bandit420]

I'd describe that as an assumption, not a fact. Sure, what happens next is important, but widening the focus obfuscates the task. Does it really matter what type of nutrients will be used in the next pot? Or does it only matter that the plant is healthy and well-prepared for whatever happens to it next?

I understand the desire to expand the discussion to later stages. That's where the fun is. It's just not what I'm wanting from this thread. I don't want to go into what growers should or could do after the transplant to the next pot. I am rather certain that we never would or could find the perfect-for-everyone, first-pot soil. We might, however, find a recipe that other soil growers could adapt to their growing style.


That has been acknowledged. We don't need to restate that which has been accepted as axiomatic. Perhaps we can also accept that there are factors other than nutrition that affect a plant's health and well-being during its time in its first pot. What about the physical and biological properties of the soil that I described in post #48? We know that root development is intense during the period in question. Why is that? If it's important, what does the plant need to root well? What do those roots (and the plant as a whole, of course) need from the soil other than nutrition?

"Cultivate the root; the leaves and branches will take care of themselves." ~ Confucius​

You don't have to do so. There are many general answers. I seek specifics. I'm trying to take this discussion to a level or two above it being a newbie question. I'm hoping to explore the science of early root development. I suspect I didn't present my intent well from the beginning, so I apologize for that. Then again, sometimes it takes a thread a while to filter down to its core purpose. I'll try to refocus the discussion to be more specific.

I think what you're actually trying to understand really does not pertain to soil but what happens the first 10 days of life, the stored energy within a seed that has nothing to do with nutrients, the effect of gravity and light at the time of germination, and how it all comes together to germinate the seed and getting the sprout to optimize performance from day 1.

Leafly is fun for general outlines of data but I like to observe in real time. I learn a lot more about what's going on with a plant. Leafly is like having a recipe book but it's missing half the ingredients in the recipes.
If you want a deep dive, check out Jorge Cervantes Cannabis Encyclopedia

 

[Amnesia]

I think what you're actually trying to understand really does not pertain to soil but what happens the first 10 days of life, the stored energy within a seed that has nothing to do with nutrients, the effect of gravity and light at the time of germination, and how it all comes together to germinate the seed and getting the sprout to optimize performance from day 1.

Once again, I acknowledge that we don't need to discuss nutrition. I must have typed that almost a dozen times by now. I'm also not trying to discuss germination, gravitropism or phototropism.

I'm trying to discuss the best qualities of a plant's first soil. This is the soil it knows after germination and before up-potting to nutrient-enriched soil—the stuff in the solo cup.

Why should we discount the role of soil in a plant's early life? If soil is unimportant, why does the plant put so much effort into growing roots at that time? If it's true that root growth is important at that time, would it help to nurture that root growth? Would it help to add Great White or Recharge to that first soil? Would it reduce the time in the solo cup? Would the microbes transfer to the next soil? If so, would it be beneficial to foster microbe growth early—in the solo cup? Would we be able to use less root growth stimulant if we started to use it sooner?

That said, I was just typing my "Let's end this." post. I can't seem to communicate what I'm trying to accomplish, so it's time to stop.

Leafly is fun for general outlines of data but I like to observe in real time. I learn a lot more about what's going on with a plant. Leafly is like having a recipe book but it's missing half the ingredients in the recipes.

I don't rely on Leafly, even if it is headquartered in my hometown. It just showed up high on the list of search results.

I had no intention for this thread to be a discussion of the stages of a plant's life. I only used the Leafly quote to exemplify how there are many models for the stages of plant growth. The stage, however, doesn't matter. We can more easily define the topic by describing the soil a plant knows after germination and before up-potting. That soil is all I hoped to discuss.

If you want a deep dive, check out Jorge Cervantes Cannabis Encyclopedia

The last time I checked, it had not been updated in the 21st century. I can look again to see if there's a newer version. You're right, though, the answers to my questions are elsewhere.

 

[Amnesia]

As the twig is bent, so grows the tree. ~ Alexander Pope​

I have been trying to find the source of a Chinese saying that goes something like this: "Knowledge is found in the leaves and wisdom is found in the roots." I haven't had any luck with my searches, but I'll keep trying. Meanwhile, it is the wisdom found in the roots that I seek. Perhaps I'll eventually have better luck with that pursuit. That said, it may be time to stop pursuing it here.

I thank everyone who tried to help.

 

[Bandit420]

Once again, I acknowledge that we don't need to discuss nutrition. I must have typed that almost a dozen times by now. I'm also not trying to discuss germination, gravitropism or phototropism.

I'm trying to discuss the best qualities of a plant's first soil. This is the soil it knows after germination and before up-potting to nutrient-enriched soil—the stuff in the solo cup.

Why should we discount the role of soil in a plant's early life? If soil is unimportant, why does the plant put so much effort into growing roots at that time? If it's true that root growth is important at that time, would it help to nurture that root growth? Would it help to add Great White or Recharge to that first soil? Would it reduce the time in the solo cup? Would the microbes transfer to the next soil? If so, would it be beneficial to foster microbe growth early—in the solo cup? Would we be able to use less root growth stimulant if we started to use it sooner?

That said, I was just typing my "Let's end this." post. I can't seem to communicate what I'm trying to accomplish, so it's time to stop.


I don't rely on Leafly, even if it is headquartered in my hometown. It just showed up high on the list of search results.

I had no intention for this thread to be a discussion of the stages of a plant's life. I only used the Leafly quote to exemplify how there are many models for the stages of plant growth. The stage, however, doesn't matter. We can more easily define the topic by describing the soil a plant knows after germination and before up-potting. That soil is all I hoped to discuss.

can look again to see if there's a newer version. You're right, though, the answers to my questions are elsewhere.

Is 2015 the 21st century? The Encyclopedia I'm talking about was published in 2015

Amazon.com

I tap out my man. I have no idea what info you're after here. All I can say is grow and it will all fall into place

 

[Amnesia]

Is 2015 the 21st century? The Encyclopedia I'm talking about was published in 2015

Amazon.com

Thanks for the reference. I did say I would check again, though. I must have been thinking of something else.

I tap out my man. I have no idea what info you're after here. All I can say is grow and it will all fall into place

Thanks for letting me know and thanks for trying.

I'm done with this thread, too. It's my fault. I haven't been able to communicate. I couldn't find a way to describe the soil in the solo cup. I also failed to engage people in a discussion about how to improve it.

 

[Zen_seeker]

Thanks for the reference. I did say I would check again, though. I must have been thinking of something else.


Thanks for letting me know and thanks for trying.

I'm done with this thread, too. It's my fault. I haven't been able to communicate. I couldn't find a way to describe the soil in the solo cup. I also failed to engage people in a discussion about how to improve it.

Unfortunately it’s a topic I have nothing to contribute.

But I did read through until it got bumpy.

 

[Amnesia]

Unfortunately it’s a topic I have nothing to contribute.

No problem. Thanks for stopping by. Thanks for the Likes.

But I did read through until it got bumpy.

My fault. It was frustrating for me, but I'll survive. I've had a heck of a problem with slow growth in the initial stages of plant growth and have yet to find a solution. My poor Amnesia Haze plants were barely an inch tall after a month. I'm thinking it's the soil, but have tried several commercial products. So, that led me to try here. As you observed, it got bumpy.

I'll probably pursue devising a medium with favorable texture, structure, density, porosity, etc. and add supplements, like Great White, Azomite, Epsom Salts and Gypsum. I'm not sure about the ratios and quantities, though.

 

[Zen_seeker]

As I only had one strain I moved from seeds to clones. I use peat pucks until I move them to cups, or go straight to cups if larger. It’s an extra step but I have the space setup for them at that size.

I used/use peat pucks for seedlings too but started just in cups/water bottles. The soil I used is the same I grow in. Nothing hot though.

I’ll keep checking your other thread.