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!"

 

[Shaded]

Ok I'm back, waaaaaaay too much info to process and individually quote here however. From what I gather you are just trying to understand and optimize the medium you are using directly after germination to provide faster/more explosive growth rates?

I am no scientist but from my deductions grow rates are directly tied to how fast the plants metabolism is working - aka how fast is it using up the sustenance that I am providing. A seedling with a 2 day dry-back cycle will grow faster than a seedling with a 10 day dry-back cycle and that's just how it is.

As per Bugbee there are 9 cardinal perameters for plant growth, what cycle of life they are in does not change these perameters.

ABOVE THE ROOT ZONE

1. TEMP
2. HUMIDITY
3. WIND/AIR VELOCITY
4. CO2

BELOW THE ROOT ZONE

5. TEMP
6. WATER
7. NUTRIENTS
8. OXYGEN

And then

9. LIGHT

What you are focusing on right now in this discussion seems to be the latter portion, or below the root zone. So how do we optimize these factors?

ROOT ZONE TEMP - keep plants elevated and off of cold surfaces. Use a seedling heat mat to promote growth after germination phase. Plant's do not like being cold, they thrive and their growth rates explode in optimal temperatures.

WATER - how quickly is the plant using the h20? The medium you choose will greatly impact this along with your other environmental factors. Which is why best is not always an easy answer and will vary from grower to grower - not all of us can grow in coco/perlite 50/50 mix or start with Rockwool. Most indoor growers use a soil which mimics the soil we will be using for the remainder of the veg and flower phase, because most of us are also running perpetually and speed isn't the end goal.

NUTRIENTS - this is up for debate and experiment, but in my experience you do not need to add ANYTHING to the medium during the seedling phase or the first 2-3 weeks. Nutrients include micro and macro nutrients or anything you would be adding to "supplement" any compound.

OXYGEN - quite possibly THE most important factor in growth rates for seedlings. So how do we optimize oxygen? Through the medium, air flow/humidity, temps and through the container we use to grow. This is where high porosity and fast dry-back becomes a very important factor into the equation. Coco with a high perlite mixture or straight rockwool would provide the closest emulation to hydro and in my opinion would simulate the highest grow rates for a seedling assuming all other factors are optimized.

Hopefully this helps you out a bit.

This is a link to the bugbee video where he breaks down each variable and what is optimal. LIGHT IS THE PRIMARY DRIVER BEHIND EVERY OTHER METRIC.

 

[Amnesia]

From what I gather you are just trying to understand and optimize the medium you are using directly after germination to provide faster/more explosive growth rates?

Yes! That's it, although I'd settle for growth that best prepares the plant for the next soil and beyond. I have a notion that plants "learn" their environment and respond accordingly. So, my thinking is that early learning is important to later growth and adaptations. Plants are very adaptable and can recover from a poor beginning, but a good beginning is better. It could shorten the overall vegetation period, if not foster a healthy plant going forward.

I'll admit I was frustrated by this thread. Apparently, I am having an unusual problem. You've seen my Amnesia Haze grow. The plants look good now, but their beginning was horrible. They sprouted quite well, but when I put them in soil, they just didn't grow well at all. After a month, they looked like miniature plants. I finally pulled them out of their pots and found dry soil under their root ball. So, the roots couldn't grow. I removed most of the soil and used my basic soil mix. That fixed the problem and they're doing well now. That initial soil problem is what led me to start asking questions about how to optimize the plant's first soil, especially for root growth.

Hopefully this helps you out a bit.

It does! It helps a lot. I am just completing my first year of inside growing and I know I have much more to learn. The Amnesia Haze is my fourth crop.

Thank you so much!

 

[Rootsruler]

Ok I'm back, waaaaaaay too much info to process and individually quote here however. From what I gather you are just trying to understand and optimize the medium you are using directly after germination to provide faster/more explosive growth rates?

I am no scientist but from my deductions grow rates are directly tied to how fast the plants metabolism is working - aka how fast is it using up the sustenance that I am providing. A seedling with a 2 day dry-back cycle will grow faster than a seedling with a 10 day dry-back cycle and that's just how it is.

As per Bugbee there are 9 cardinal perameters for plant growth, what cycle of life they are in does not change these perameters.

ABOVE THE ROOT ZONE

1. TEMP
2. HUMIDITY
3. WIND/AIR VELOCITY
4. CO2

BELOW THE ROOT ZONE

5. TEMP
6. WATER
7. NUTRIENTS
8. OXYGEN

And then

9. LIGHT

What you are focusing on right now in this discussion seems to be the latter portion, or below the root zone. So how do we optimize these factors?

ROOT ZONE TEMP - keep plants elevated and off of cold surfaces. Use a seedling heat mat to promote growth after germination phase. Plant's do not like being cold, they thrive and their growth rates explode in optimal temperatures.

WATER - how quickly is the plant using the h20? The medium you choose will greatly impact this along with your other environmental factors. Which is why best is not always an easy answer and will vary from grower to grower - not all of us can grow in coco/perlite 50/50 mix or start with Rockwool. Most indoor growers use a soil which mimics the soil we will be using for the remainder of the veg and flower phase, because most of us are also running perpetually and speed isn't the end goal.

NUTRIENTS - this is up for debate and experiment, but in my experience you do not need to add ANYTHING to the medium during the seedling phase or the first 2-3 weeks. Nutrients include micro and macro nutrients or anything you would be adding to "supplement" any compound.

OXYGEN - quite possibly THE most important factor in growth rates for seedlings. So how do we optimize oxygen? Through the medium, air flow/humidity, temps and through the container we use to grow. This is where high porosity and fast dry-back becomes a very important factor into the equation. Coco with a high perlite mixture or straight rockwool would provide the closest emulation to hydro and in my opinion would simulate the highest grow rates for a seedling assuming all other factors are optimized.

Hopefully this helps you out a bit.

This is a link to the bugbee video where he breaks down each variable and what is optimal. LIGHT IS THE PRIMARY DRIVER BEHIND EVERY OTHER METRIC.

Excellent! Also an explanation as to why those findings are the best and the processes that happen to make them the best. One thing.....these are going to change depending on grow style. Oganic vs synthetic. Soil mediums.

 

[Shaded]

Yes! That's it, although I'd settle for growth that best prepares the plant for the next soil and beyond. I have a notion that plants "learn" their environment and respond accordingly. So, my thinking is that early learning is important to later growth and adaptations. Plants are very adaptable and can recover from a poor beginning, but a good beginning is better. It could shorten the overall vegetation period, if not foster a healthy plant going forward.

I'll admit I was frustrated by this thread. Apparently, I am having an unusual problem. You've seen my Amnesia Haze grow. The plants look good now, but their beginning was horrible. They sprouted quite well, but when I put them in soil, they just didn't grow well at all. After a month, they looked like miniature plants. I finally pulled them out of their pots and found dry soil under their root ball. So, the roots couldn't grow. I removed most of the soil and used my basic soil mix. That fixed the problem and they're doing well now. That initial soil problem is what led me to start asking questions about how to optimize the plant's first soil, especially for root growth.


It does! It helps a lot. I am just completing my first year of inside growing and I know I have much more to learn. The Amnesia Haze is my fourth crop.

Thank you so much!

Well I will tell you two things!

1. I dislike FoxFarms of any kind and refuse to use it EVER. I know it works for some and I'm not knocking them, I just see way too many issues from other growers that use the stuff. Seems like consistency is at the lowest of their product priority list. I stick with inert soils so that I know EXACTLY what is being put into them.

2. Roots expand in search of water. This is why full saturation followed by a dry-back phase is important. When you see dry spots under the root ball it's probably a good sign that the pot wasn't getting saturated enough to promote root expansion. Or the pot size was too large when you transitioned and the plant just didn't get enough time to fill out the pot with roots.

 

[Amnesia]

One thing.....these are going to change depending on grow style. Oganic vs synthetic. Soil mediums.

I wrote at the top that my grow style is organic and that I'm following @Shaded's Gaia Green method.

I believe the effect on later methods may be negligible. The amount of soil in the first pot is trivial compared to the amount of soil in subsequent pots. The triviality would be especially true as the roots spread to their new soil. An exception may be the presence of helpful microorganisms that probably would spread after the transplant. I am not sure about that, though, so I asked about it in one of my posts. Micronutrients might be somewhat helpful, but would need to be amended to be significant. Macronutrients are not used, so they aren't a factor at all.

Even if the effect on grow style did matter, anyone reading this could adjust the mix to their own specifications. I thought that was widely understood. A universally optimal mix would be nice, but that can be little more than a fantasy. I'm certainly not trying to tell anyone what they should do, but I would be happy if my idea of a specialized starter mix helped someone.

 

[Max]

This is what we have down here.hope this works.check out the comments on the items. Just tap on an item https://www.organicgardeningsolutions.com.au/

 

[Shaded]

I wrote at the top that my grow style is organic and that I'm following @Shaded's Gaia Green method.

I believe the effect on later methods may be negligible. The amount of soil in the first pot is trivial compared to the amount of soil in subsequent pots. The triviality would be especially true as the roots spread to their new soil. An exception may be the presence of helpful microorganisms that probably would spread after the transplant. I am not sure about that, though, so I asked about it in one of my posts. Micronutrients might be somewhat helpful, but would need to be amended to be significant. Macronutrients are not used, so they aren't a factor at all.

Even if the effect on grow style did matter, anyone reading this could adjust the mix to their own specifications. I thought that was widely understood. A universally optimal mix would be nice, but that can be little more than a fantasy. I'm certainly not trying to tell anyone what they should do, but I would be happy if my idea of a specialized starter mix helped someone.

+1

@Rootsruler just meant that even if both parties are growing in soil mediums, grower A using synthetics is going to most likely use a different medium compared to grower B using organic dry amends. Synthetics and coco for example go together really well due to the CEC rates of coco and the high fertigation or frequent watering also goes together better with synthetics. Could you imagine using synthetic fertilizers and having to wait 7-9 days for your peat based medium to dry up? yikes

 

[Amnesia]

Well I will tell you two things!

I'm always happy to hear what you have to say. You have always been helpful. It's just taking me some time and experimentation to transition.

1. I dislike FoxFarms of any kind and refuse to use it EVER. I know it works for some and I'm not knocking them, I just see way too many issues from other growers that use the stuff. Seems like consistency is at the lowest of their product priority list. I stick with inert soils so that I know EXACTLY what is being put into them.

I have the problem of using up supplies. FF may not be the best and I may try another brand eventually. The local hydro shop has plenty of Promix. But I have two big bags of FFOF sitting on top of a big bag of Miracle Grow left over from my first crop when I was told not to use MG. I'm using the remaining MG for other gardening. So far, the mix of FFOF with previously used soil seems to be working. I assume that, eventually, any nutrients that were part of the initial soil will probably be depleted over time.

2. Roots expand in search of water. This is why full saturation followed by a dry-back phase is important. When you see dry spots under the root ball it's probably a good sign that the pot wasn't getting saturated enough to promote root expansion. Or the pot size was too large when you transitioned and the plant just didn't get enough time to fill out the pot with roots.

Oh, I tried to saturate the soil. It was a 3- or 4-inch pot. It wasn't a solo cup, but it was the same size as one. It was just lousy, off-the-shelf soil. I suspect I would have been better off using my basic soil mix. I wish I had taken pictures. I know what I saw, though. So, what you said about saturation and dry-back to promote root expansion became my quest.

 

[Shaded]

@Amnesia you could even take that FF and Miracle Grow soil and just flush it completely. That should get rid of any nutrients that is in the mix and then you're just left with the soil? Just an option.

Someone like @Moe.Red or @Bandit420 need to 3D print some smaller nursery sized air pots that we can buy from the store

 

[Rootsruler]

@Amnesia you could even take that FF and Miracle Grow soil and just flush it completely. That should get rid of any nutrients that is in the mix and then you're just left with the soil? Just an option.

Someone like @Moe.Red or @Bandit420 need to 3D print some smaller nursery sized air pots that we can buy from the store

Why would you throw away nutrient that you paid for? Both of those mixes are hot. Take some low dose potting mix or coco and mix down the strength. Throw in some perlite for the extra drainage. I'd go 1:1. It should reduce the hot mix by around 25%.

 

[Shaded]

Why would you throw away nutrient that you paid for? Both of those mixes are hot. Take some low dose potting mix or coco and mix down the strength. Throw in some perlite for the extra drainage. I'd go 1:1. It should reduce the hot mix by around 25%.

it was an option for using hot soil she already has, while reverting it back to an inert state. @Amnesia had made a comment about wanting to use inert soil but being stuck with a surplus of FFOF/Miracle Grow

 

[Amnesia]

Someone like @Moe.Red or @Bandit420 need to 3D print some smaller nursery sized air pots that we can buy from the store

Nice! They're looking for prizes for contests. This could be a good one.

 

[Amnesia]

My current mix is old and new soil combined in a 1:1 ratio. Then I mix in EWC, perlite and rice hulls. I add nutrients when I use the soil.

Using up what I have in stock and acquiring new stock is a bit of a problem. It makes it hard to change direction. I began using synthetic nutrients, then decided to transition to organic growing. So, the two grows I'm finishing now are in that transition category.

 

[Amnesia]

We trekked into the city today. Among our many stops was the hydro store I recently found. My intent was to buy some ingredients for a starter mix, but the nice man looked at me like I was an idiot and said I should just buy some. So, not wanting to be an idiot in the eyes of a stranger, I bought some. I also bought some roots organics stuff because I actually am an idiot. Here's what we bought:

 

[Shaded]

We trekked into the city today. Among our many stops was the hydro store I recently found. My intent was to buy some ingredients for a starter mix, but the nice man looked at me like I was an idiot and said I should just buy some. So, not wanting to be an idiot in the eyes of a stranger, I bought some. I also bought some roots organics stuff because I actually am an idiot. Here's what we bought:

View attachment 7997

Did the nice hydro store man also tell you that he was selling you a coco based starter soil? Just curious as I thought you mentioned that you didn't want to be watering that frequently.

ROOTS ORGANICS COCOPALMS​

INGREDIENTS
Washed and age cured coconut husk with limestone (pH adjuster)

vs

ROOTS ORGANICS ORIGINAL POTTING SOIL​

INGREDIENTS
Perlite, Coco Fiber, Peat Moss, Composted Forest Material, Pumice, Worm Castings, Bat Guano, Soybean Meal, Alfalfa Meal, Fishbone Meal, Kelp Meal, and Greensand. Also contains beneficial mycorrhizal fungi: Funneliformis mosseae, Rhizophagus intraradices, Septoglomus desertícola to enhance uptake of plant nutrients, increase root biomass, and help container grown plants resist stress

 

[Amnesia]

Did the nice hydro store man also tell you that he was selling you a coco based starter soil? Just curious as I thought you mentioned that you didn't want to be watering that frequently.

ROOTS ORGANICS COCOPALMS​

INGREDIENTS
Washed and age cured coconut husk with limestone (pH adjuster)

vs

ROOTS ORGANICS ORIGINAL POTTING SOIL​

INGREDIENTS
Perlite, Coco Fiber, Peat Moss, Composted Forest Material, Pumice, Worm Castings, Bat Guano, Soybean Meal, Alfalfa Meal, Fishbone Meal, Kelp Meal, and Greensand. Also contains beneficial mycorrhizal fungi: Funneliformis mosseae, Rhizophagus intraradices, Septoglomus desertícola to enhance uptake of plant nutrients, increase root biomass, and help container grown plants resist stress

We had a bad day today.

 

[Shaded]

We had a bad day today.

Well the saving grace is the Light Warrior which looks like it should be pretty decent stuff!

"Contains an organic blend of mycorrhizal fungi (a powerful root stimulator), sphagnum peat moss, horticultural perlite, earthworm castings, granite dust, humic acid and oyster shell (for pH adjustment)"

 

[Amnesia]

Well the saving grace is the Light Warrior which looks like it should be pretty decent stuff!

"Contains an organic blend of mycorrhizal fungi (a powerful root stimulator), sphagnum peat moss, horticultural perlite, earthworm castings, granite dust, humic acid and oyster shell (for pH adjustment)"

Well... Thanks. The hydro store (if that's what it's called) is a small business in a small town. It's run by a young couple who usually have their toddler in the store. So, we want to give them business. He asked what type of coir we wanted and, having no experience with it, we went with his recommendation. That was the uncompressed type.

We're currently finishing two crops in our two tents, so there's no need to start new plants or mix soil right now. We're mostly just working on supplies for the fall when we plan to grow again. I'll try the Light Warrior the next time I start some seeds.