Repotting

[Brwnthmb]

This is my first time at indoor plants.
what schedule should a grower be on when it comes to flower pot size? That is; from seedlings to mature plants, what size pots do you use, and when do you increase the pot size? Do you use a clay pot, plastic, or other?
thanks

[Gator]

I start with a 1 gallon fabric pot,and pot- up when they are ready, usually to a5 or7 gallon, fabric pot is your best choice

[Gingerbeard]

Every time you transplant you open yourself to plant damage and always have a modicum of transplant shock that will temporarily slow down growth.
Remove the cotyledons on your plant.
Fill a 7-gallon pot of any of the materials you mentioned with whatever grow medium you decide to use. You can literally walk in your local garden supply store and pick a pot you think looks nice, whatever the material. The more porous the material, the more often you will water. Bags have handles. While porous fabric pots breathe, porous clay pots wick moisture from soil. Tapered pots are easier to knock over.
What you have been using for soil looks fine. Fill it to 2" to the top of the pot. Water the pot so the water pours out the bottom. Wait 12 hours.
Remove the plant, soil, and root ball from the peat pot it is in. Cutting down the sides of the pot might be the easiest.
Dig a hole in your pot deep enough so the cotyledons would have been level with the soil. Put your plant in and fill the hole. Water the pot.
Grow.

[Gator]

Did I miss something???

[Gingerbeard]

This is ongoing from another post.
Click on the original posters handle to see what's been going on.

[dirtymike]

But not to much, easy at the start and fast at the finish. SHBT

[Brwnthmb]

I start with a 1 gallon fabric pot,and pot- up when they are ready, usually to a5 or7 gallon, fabric pot is your best choice

I assume then that you do your first transplant putting the seedling into a 1 gallon fabric pot. I have a second group of seedlings that have not been damaged by overwatering and light burn. I read that a good rule of thumb is to transplant the seedling when its follage reaches the diameter of it as container. Do you agree? Or would you transplant this one now before it reaches the pot diameter? And when you say you would start in a one gallon fabric pot, do you mean that you would germinate the seed in a one gallon or do you mean that you would transplant it first into a one gallon?

[Brwnthmb]

Every time you transplant you open yourself to plant damage and always have a modicum of transplant shock that will temporarily slow down growth.
Remove the cotyledons on your plant.
Fill a 7-gallon pot of any of the materials you mentioned with whatever grow medium you decide to use. You can literally walk in your local garden supply store and pick a pot you think looks nice, whatever the material. The more porous the material, the more often you will water. Bags have handles. While porous fabric pots breathe, porous clay pots wick moisture from soil. Tapered pots are easier to knock over.
What you have been using for soil looks fine. Fill it to 2" to the top of the pot. Water the pot so the water pours out the bottom. Wait 12 hours.
Remove the plant, soil, and root ball from the peat pot it is in. Cutting down the sides of the pot might be the easiest.
Dig a hole in your pot deep enough so the cotyledons would have been level with the soil. Put your plant in and fill the hole. Water the pot.
Grow.

So you are saying to bury the plant up to its cotyledons in a 7 gallon pot, so it can sprout new roots along its stem? Sounds good. I was afraid these were toast.
I have a question on watering. I read on this site I believe about watering and pot size, and it said that if the pot is bigger than the plant that the roots can drown because the plant doesn’t take up the water fast enough. So the trick is to provide the correct amount of water. What I gathered is that it is best to water close in around the plant, and water just enough and often. Do you have any additional advice?

[Gingerbeard]

The picture you just posted is not the picture you posted in your previous post. I would put this one down 1" below the coty's in a 7-gallon bag. I say 7-gallon bag because your other plant is photo and I assume this one is as well. That means you have the opportunity to grow those plants into 7-gallon plants: Big 'uns. I say bags because bags have handles, are easy to manipulate, self prune roots, and are stable. Yeah, I'm clumsy.
Everything you said about watering is golden in my book. Keep the watering to a little past the drip line (edge of the canopy). Like people, plants do not drown from too much water. People die from not getting enough clean oxygen to their brains. Plants die from not getting enough clean oxygen to their roots.
I no longer transplant for the reasons I gave. My first grows went seed on towel, Solo cup, one gallon, five gallon. I killed a lot of plants by breaking the toweled sprout, dropping Solo cups, and stunted plants after transplant. I now put my seeds in 5-gallon coco/perlite bags and let them do their thing.

[Brwnthmb]

I need to make sure I understand your advice.
Are you saying to bury both plants up to their cotyledons (small non serrated leaves)?

[Brwnthmb]

What do you use for a saucer under the 7 gallon pot? I was going to order fabric pots from Amazon and the dimensions on the 7 gallon pot is 15” on diameter.

[Brwnthmb]

Another question; watering a small plant in a big pot;
How do you know that the amount of water is correct?
I don’t have my 7 gallon fabric pots yet but I put one of my problem plants in a 10” diameter clay pot and watered it just below the leaves (or close to that). That leaves a lot of soil outside of the plant unwatered. Also the soil around the stem drinks a lot of water, or it could, and I don’t want to overwater. How do you know when you’ve watered it enough? How do you know that it’s time to water again?
Edit:
I failed to saturate the soil in the larger pot and wait 12 hours. I missed that the first time I read your instructions. (It may work out ok. I think I got too much water around the stem. The soil outside of this will soak more of this up since I didn’t saturate it.)

[dirtymike]

"quote" Gingerbeard someone keeps repeating you.!

[Gingerbeard]

My reply about removing and burying up to the cotyledons was in reference to your 'Sick Plant' thread as you had not posted the picture in post #6 in this thread.
For the plant in this thread, bury it up to an inch below the cotyledons (I did not say remove them. They are healthy on this plant.)
For your other plants, I don't know what they look like so won't say anything.
A thing about transplanting deeper is the part of the trunk of the plant that gets covered by soil will grow roots it otherwise would not.
When to water comes with a little experience. My method is by weight. I know how dry my plants are by lifting them, one of the handle bonuses. For no experience, I would start with a simple moisture meter. Get the biggest and most expensive you want, but a simple two prong thing you stick in the dirt is just fine.
How much to water also comes with experience. I know one gallon does my bags perfect when they get going. In early stages, man, I'm sorry, but it's experience. It seems like a continuous, oxygenated drip would be best for seedlings, but don't quote me on that.
I grow in 5-gallon because of the size of my tent. 4, 5-gallon plants max my space. If I had lots of space I would be topping feminized in at least 7-gallon. You can find saucers and stands of any size online.
Small plant-big pot. One good watering of the whole pot, then follow the drip-line.

[Gator]

Potting up tomorrow when the 3 gallon pots are here

[Brwnthmb]

Is 3 gallon the largest size you will use? I’m curious for several reasons. If 3 is not the largest, why do you use an intermediate size? If it is the largest, what height plant do you expect (and yield)? I think 3 gallon is about right for me and my space limitations (10” diameter). (I’ll return the 7’s.)

[Gingerbeard]

Brwnthmb It's time to head to the website and do some research. I see you doing things and planning on doing things and missing or forgetting things.
Take a look at the sample grows and lifecycle of cannabis. Figure out what you can do with what you have, where you want to go, and what you need. I know that's what you are doing but you are not giving the whole picture and we cannot give well informed advice.

[Gator]

I went with 3 gallon pots because 5 gallon pots are too big for the tent, I'm trying to buy some time while the 3 plants in the flower space finish up,then I'll pot up to the 7 gallon pots,veg for a few weeks and flip the lights to flower

[Gator]

Even the 3 gallon pots are a bit crowded

[Rootsruler]

My transplant game goes like this. Seed in a vertical germinator or, if you don't have a VG, in a paper towel. Once the seed has sprouted, I tear away the part of the towel that doesn't have the tap root and any other secondary roots and plant the rest. BTW make sure to use the cheapest, shittiest paper towel you can find. PT's like Brawny have cloth woven into them to make them tougher. You want something akin to toilet paper so that the paper towel practically falls apart when you get it into the soil. Seeds have certain enzymes and microbes in and on them that will be in the towel material so planting the towel in the soil will help in transferring those enzymes and microbes to your soil where you want them. The PT will break down over time.

Sprout in a clear solo with a red solo as a sleeve so I can remove clear solo and see how root development is coming along without disturbing the roots. Fill your solo to the top. I don't go by top growth because root growth is the most important thing for me at this time. I also water in some AN Voodoo Juice, which is liquid bacteria, to help in bumping up the microbial colony developing in the soil.

Once the roots have reached the bottom of the cup and are starting to wrap at the bottom I'll take a one gallon nursery pot, fill it to the point where, when I place the clear solo in the pot, the soil line is about an inch from the top edge of the pot. This will place your tap root and any other major roots right at the edge of the perched water table your media produces. Far enough away from the PWT to not overwater them and close enough for the main roots to dip into the PWT to get a nice drink of water. I place the clear solo in the pot and side fill the remainder, gently compressing the soil to eliminate air pockets. Once the side fill and soil compression are done, I remove the clear solo leaving a hole in the shape of the solo. I add a dose of mycorrhizae in the hole then, I slide the sprout out of the solo and gently place it in the hole. I've found the best time to do this is when the soil is semi dry or dry. This makes it easier to slide the plant out of the cup as the soil will usually pull away from the sides when it gets dry and shrinks. I'll gently compress the soil so that the roots have good contact with the new soil and water them in.

I repeat this process once the plant has reached the height I want them to be when I transplant the plant into its final pot.

I use 7 gallon cloth pots as my final pots. I find this size tends to give the plants enough biomass to keep deficiencies at bay along with my feeding them salt ferts but final pot size really depends on how big you want to grow the plant. 7 gallon works for me if I'm doing a 4-6 week veg. If I'm going to veg longer then I go to 10 gal but that scenario would be more conducive to outdoor in a pot growing. 5 gallon will also work if space is an issue but you'll need to stay on top of your feed schedule to make sure they are getting the nutrition they need and not get deficiencies which take the plant out of growth mode and into recovery mode elongating the overall time it takes to get your flowers to maturity or lowering the final dry weight.

I like cloth pots but Aero Pots are probably the best at getting the maximum amount of oxygen to the rhizosphere.

This is a long post that I'm going to make even longer by posting some information that really helped me understand the relationship between pot size, media choice and watering practices. I am not the author of this information. Read and learn.

This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm not presenting my opinions as facts so take from this what you like. I will be putting it in subsection format for easy reference.

First I want to make an important point to take into consideration before reading. The tap root will grow directly downwards to the bottom of the container before spreading out.

PERCHED WATER TABLE

What is it?

The perched water table is basically the height of the saturation zone where capillary action and gravity cancel eachother out. This area will be saturated with water and will be responsible most growers issues with watering practices especially in soil grows.

WHAT IS CAPILLARY ACTION

CAPILLARY action is is the combination of the cohesive and adhesive properties of water.

In short adhesion is water clinging to the media (think of it like wicking or soaking up)

Cohesion is where the water clings to itself.

So as the water is wicked up (adhesion) it pulls more water with it through Cohesion and at the point gravity and these properties cancel eachother out is the perched water table.

This perched water table will always remain the SAME HEIGHT and will always stay saturated unless taken up by the plants or evaporates when the pot dries out. No matter the container height, depth or volume of media. So if a tall skinny container had a perched water table of 1" then a short wide one of the same media will also have a perched water table of 1". Which means the ratio of water to air in a wide pot will be higher than a tall skinny pot which will have a higher air to water ratio... keep this in mind as we get further.

Different media's have different perched water tables. A more absorbent media will have a higher perched water table than a less absorbent media... REMEMBER THIS as it makes a big difference on pot selection for your media.

DIFFERENT MEDIA

Water holding capacity is directly related to the height of the perched water table so soils with more clay or silt and less sand will have a higher perched water table than those with more sand because sand is a larger particle.

The larger the overall particles of the media the lower the perched water table and better the drainage.

By adding things like perlite or vermiculite (while vermiculite is good at absorbing water it also improves drainage so its helpful in keeping a more even level of moisture throught the media while increasing drainage due to its size) we can lower the perched water table by reducing the wicking (adhesion) ability and creating more space between particles overall reducing the cohesion effect and inturn the height of the perched water table.

Media's like peat based or coco have a much higher drainage and lower perched water table than soil and are therefore less susceptible to over watering but will require more frequent watering due to the lower water holding capacity.

Adding thing like perlite or hydroton to the bottom of the pots will NOT reduce the water table but instead raise it. This is because as I said the height of the water table will not change for a given media. So if you add things like that to the bottom you are essentially just moving the water table up.

Basically the larger the particles IN the media the better drainage and lower the water table.

If you want to see the height of your perched water table use a clear cup with drain holes fill with media and saturate it. Wait a few hrs for drainage and then come back and look. You can see the difference in the varying media's if you want to experiment.

If you feel you have over watered or your perched water table height is to high you can simply tilt your pot on a 45 degree angle and release more water from the media as runoff. To help visualize think of it this way if you have a perched water table of 2”. You can draw an imaginary horizontal line at that height, when you tilt the pot you have less media below that line and therefore you will have less water in the pot after tilting it.

POT SIZE

I have already covered this a bit but my opinion is if you are using a media with a higher water table you will benefit from taller narrower pots and if using a media with a lower perched water table the shorter wider ones may benefit you depending on your watering practices.

I prefer the taller over wider no matter the media as I choose to water often and have a higher air holding capacity and lower water table but that can work against you if you can't water as frequently and as plants grow it can greatly increase the frequency required as the roots will be pulling the water out of that saturation zone quickly. So you may want to use taller pots for small plants and transplant into a wider one as they grow.

You also don't want a pot that's to tall and the top portion of the media is drying out to fast while the bottom is wet.

Let's use seedlings as an example take a solo cup or a large container... the water table will be the same height in either. I see so often ppl trying to water a tiny bit in circles or mist the surface and for lack of other words IT DRIVES ME NUTS. Why because the roots are so shallow they are not at risk of being over watered. Remember though, tap roots grow straight down so we to be mindful as they grow depending on the gas exchange of the media that the majority of roots are not sitting in the saturated zone with poor gas exchange because this will cause lack of oxygen that we incorrectly refer to as overwatering which is actually the cause not the symptom.

It's important to fill containers to the top to give us a good amount of space above the perched water table that high in o2. If you fill a solo cup halfway with soil it's likely to be sitting in the saturation zone and will not do well.

Also going to make the point that plants will be most susceptible to overwatering when the roots first hit the bottom and spread out until they fill the bottom and start moving back up out of the saturation zone. So again it may be more beneficial to use a taller narrow pot for the early stages of growth (2-4 weekss depending on growth) and transplant into a wider pot as you go. After the transplant almost all of the roots will be above the saturation zone and it become much harder to over water. New roots will again work their way down into the saturation zone but you will have plenty above so its less likely to over water and why uppotting as you go I see as a benefit instead of starting in a large wide container.

POT MATERIAL

Some prefer plastic others fabric, air pots etc.

This can affect the perched water table by evaporation as the lager the exposed surface area the more evaporation that occurs from the media in say fabric pots. This imo has a few benefits.... slightly reducing the perched water table but more so the exposure for gas exchange that's happening and that's a good thing for o2 levels in the root zone that I feel are directly related to growth rates and I'll explain why going a bit off topic for a second.

It's no coincidence that the fastest growing media's have the highest amounts of o2 and gas exchange.... for eg aeroponics have unlimited to rich o2 and water. Hydro similar with slightly less o2, soiless media's such as coco and I would possible include peat and last soil. If you notice they are in order of growth rates and its not hard to see the difference in thier air holding capacity in that order. And the fact that larger particles also have a better gas exchange rate. This is important because the plants take in oxygen and expell co2 in the rootzone as do the microbes on top of that so good gas exchange is important for both.

Just a note... air pruning has nothing to do with the benefits of fabric pots all it does is signal the roots to grow in a different direction.

But let's get back on topic of watering and how it's affected.

TEMPERATURE AND HUMIDITY

The warmer the temps the more evaporation occurs.

The lower your humidity the more evaporation occurs

The more surface area exposed to air movement (wind) the more evaporation.

Think those don't need an explanation. But the difference in pot material coupled with these environmental factors will have an impact on your watering needs.

The temperature of the media not only affects evaporation but also directly affect the temperature of the plant and leaf temps. This has a large impact on nutrient uptake and transportation.

First let me say that this next part is opinion and I will gives my reasoning for my opinions. With the exception of hydro (leaving this part out as this post is about watering not hydro) roots like to be about the same temperature as the leaves contrary to what's talked about from many prominent growers in the industry but not all like Mr.Bruce Bugbee. IMO ideal root temps are the same as ideal leaf temps and overall plant temps especially since the root temps have a large impact on the plant and leaf temps. What are ideal temps imo and many studies show that leaf temps (NOT AIR TEMPS) of around 77f are most efficient. So how does a cool rootzone impact the plants negatively? Well it's 2 fold because of the cool temps the viscosity (measument of flow rate) of the sap will decrease so its harder for the plant to move the nutrients through the plant. The other is absorption and one fact is that in a cooler rootzone the concentration of nutrients is higher (but aqua you just said it slows absorption) well it does as the nutrients build up in the roots it can absorb less and this has a direct impact negatively on the plant. It may appear to be overwatered because the plant is now struggling to take up and use oxygen. Add that to the slowed transpiration rates and you have the same symtom many refer to overwatering which againnos lack of o2. Now take a cold rootzone where the plants slow water uptake and then add the saturation zone to it and you can see the road to correction and recover is a long one and can have huge impact on growth and yields.

So, get your pots up off the floor

WET AND DRY CYCLES

in soil and peat with higher water tables or with wider pots or combination of wet and dry cycles are important. This is to allow the dry back (including the uptake of water from the saturation zone) to prevent symtoms of over watering and help with o2 levels. Remember the majority of roots will end up in the saturation zone with these media's or with wider pots. Which can become depleted of o2 quickly as gas exchange is lower in water and media made up of smaller particles. This is where pot size and shape are important for the size of plant. You have a small plant in large container and there is no way it can take up enough of the water in the saturation zone fast enough to get air exposure in a media that has low gas exchange and majority of the roots. So it's important to choose a pot size that will allow for this. It's also why using the finger method to gage watering is poor and lifting the pots is much better... when they are light you know they have taken up a good portion of the saturation zone and are ready to be watered again.

This is much less of an issue when using soilless like coco or peat/perlite.