Permanent/reusable 4" seed-starting pots?

Every year I start a bunch of seeds about 8 weeks before the last frost. I reuse whatever pots I have on hand. Anyway, do to space limitations and older pots wearing out, I'm looking for some 3.5" or 4" reusable square seed pots I can reuse year after year to fit in 1020 trays.

Correct me if I'm wrong, but tomatoes would likely get root bound in a 2" or 2.5" square pot after only four or five weeks - well before my eight week planting time. So I'm looking for 3.5" or 4" square pots.

The probably is, most companies sell reusable 2" square pots, and *disposable* 4" pots. And most 4" pots are round, not square. But even the square ones seem disposable and fragile.

Does anyone know where I can get sturdy and reusable 3.5"/4" square seed starting pots?

Johnny Seeds sells 3.5" square pots. Has anyone used these for multiple years now?

I’ve been using 4” and 3.5” for close to 7 years now. Seeing the condition they’re in, I think I will get at least 7 more out of them.

I try to take good care of them as much as possible. When I plant the starts in the garden, I make sure the pots are empty and store them nested in each other, and out of sunlight.

For root bound, I don’t know how many plants you’re growing, or if this is doable: I have a neighboor that pots up his tomatoes to 1.5 and 2 gallons before transplanting. He does get nice plants, and it works well for his 20 tomatoes he’s growing. I cannot do that with my 100-120 plants every spring, so mine do get root bound sometimes. It’s not a big deal, and they do spring back quickly after getting in the ground.

For root bound, I don’t know how many plants you’re growing, or if this is doable: I have a neighbor that pots up his tomatoes to 1.5 and 2 gallons before transplanting. He does get nice plants, and it works well for his 20 tomatoes he’s growing. I cannot do that with my 100-120 plants every spring, so mine do get root bound sometimes. It’s not a big deal, and they do spring back quickly after getting in the ground.

I do about the same as you each year - somewhere around 100, give or take (tomatoes, peppers, etc...). 3.5" or higher doesn't give me root bound in the 8 weeks, but I assume the 2" pots would be too harsh on the tomatoes.

Liv Smith wrote:I’ve been using 4” and 3.5” for close to 7 years now. Seeing the condition they’re in, I think I will get at least 7 more out of them.

Who's 4" and 3.5" pots are you using?

Currently, I just use leftover ones from plants I've bought at stores, but I need more, and most online seem incredibly fragile.

There are people making silicone ones, but all I have seen are uber $$$

Bootstrap farmer seems to make the best flats, but I don't know if they make larger pots.

I will need some too.

R Scott wrote:There are people making silicone ones, but all I have seen are uber $$$

Bootstrap farmer seems to make the best flats, but I don't know if they make larger pots.

I will need some too.

Yea, I was looking for permanent flats too, but found Bootstrap and decided to use theirs. Now I'm just trying to decide if I want 1020's or 1010's. I wish they'd offer 1015's. =P

Bootstrap only provides 2.5" pots, not 3.5", as far as I can see.

I've noticed over the last 5 years that the quality of "disposable plastic" plant pots has deteriorated to the point that 1-3 uses is about it, compared to 10-20 uses from the old ones if cared for. The "square" part is the kicker. I can think of some ways you could make "round" easily, but square is tougher.

I have used some coir pots but I've only seen round and they're single use, but at least they build soil.

I only need small numbers, so I make "extra-deep" paper pots (3 1/2"). They're single use, but biodegradable and tend to go moldy if not managed well and I don't normally try to get 8 weeks out of them.

Could you build them yourself? Wood, clay or rink-board?

Jamin Grey wrote:

Who's 4" and 3.5" pots are you using?

Currently, I just use leftover ones from plants I've bought at stores, but I need more, and most online seem incredibly fragile.

I bought mine new from one of our local feed/gardening supplies stores.

I know what you mean about the plastic being thinner every year. Unfortunately.

Do you guys see many of these plastic Juice bottles?

If they were chopped 4" from the bottom and a piece of corrugated cardboard placed to divide it roughly in two, would it do the job? It would delay them going to the landfill and if they were stored out of the sun when not in use, I'd expect they'd last a minimum of 5 years.
Of course you'd have to ask all your friends, neighbors and co-workers to save them for you!

I don't know how they'd fit in the flats mentioned, but I also read of a couple who made their own wooden flats because they could make them deeper and they lasted longer.

 It might be easier to find plastic cups.
Hit the garbage can after a family reunion.
Or at a bar or festival.
They aren't usually square.

I use 3 for each plant.
The 1st one is cut vertically with 3 slots all the way down the sides.
That goes in a cup with holes in the bottom,..
this second cup basically holds the first cup together,..
because cup 1 falls open.
When it's time to plant I pull the second cup off,
open one side of the 1st cup and put my hand there while I remove the split cup.
This leaves the plant laying in my hand.

The first 2 cups usually go in another cup that doesn't have a drain.
So I don't have to water young plants as often.

I see so many disposable cups of all different sizes.
And they last a few years if they aren't in the sun too long.
So I store them in the dark after planting.

I ordered some net pots for seed starting but the ones at my price point were flimsy.
I do have a roll of mesh gutter covering that could be turned  into cylinders and packed with potting soil.

I'm considering  using sections of corrugated black drain pipe.
If they need something to close the bottoms, I might use window screen or nylon stocking and hold it on with zip ties.
On the other hand, people make pots from toilet paper tubes and close the bottoms by cutting and folding flaps.

Jay Angler wrote:I've noticed over the last 5 years that the quality of "disposable plastic" plant pots has deteriorated to the point that 1-3 uses is about it, compared to 10-20 uses from the old ones if cared for. The "square" part is the kicker. I can think of some ways you could make "round" easily, but square is tougher.

I have used some coir pots but I've only seen round and they're single use, but at least they build soil.

I love those coir pots! I use those as well, and am about to order some more, but I feel a tad guilty about using disposable material, rebuying it every year, and also worry about e.g. economic collapse or recession where I don't have materials I am dependent on. I loved 2020 for that reason - it was a good practice run!

The coir pots survive the eight weeks just fine before being buried.

Making permanent ones myself I assumed would be much more expensive, but putting a little more thought in it, I bet I could take a square downspout, cut it into 4" sections (netting 30 cups out of rust-proof aliminum!), smooth the edges to prevent cutting myself, and cut a plastic bottom (with water holes drilled through) for it.

Assuming $12.50 for a 120" downspout, and add $2.50 ($10 for plastic sheet material, divided between four downspouts), we're talking $0.50 per rust-free lifetime usable pot! That's very tempting, if I can cleanly grind the edges down so they aren't jagged.
That's $50 for 120 permanently reusable pots, that compactly (squarely) use up the space. That'd fit 15 pots per 1020 tray.

They also have 2.5x2.5 vinyl downspouts. I probably wouldn't mind 2.5" if I can make the pots substantially deeper than normal 2.5" pots. I could easily sand down the edges of vinyl.
Menards has even more sizes - 2x3, 3x4, etc... at even better prices - $10 per 120".

This is a real possibility. I'll probably end up just taking a gamble on pre-made storebought pots as I already have too many projects on my hands, but I like this downspout idea.

Jay Angler wrote:Do you guys see many of these plastic Juice bottles?

I started collecting those this year, and have been using them for storing rice! Using vacuum packets, they are perfect for storing rice, and ostensibly last for over a decade. They store nearly exactly 3.75 lbs of rice or beans each, and require only a single 100 cc oxygen absorber.
I used to store my rice in half-gallon mason jars, vacuum-sealed with a FoodSaver jar attachment, and can personally attest to vacuum-sealed mason jars of rice lasting 9 years before I opened them and they still tasting 100% normal (and I'm very finicky when stuff tastes "off").
I'm hoping these kind of #1 PETE/PET recycling bottles are supposed to last over a decade for food storage. Sadly, milk gallons and other #2 HDPE bottles cannot be used, as they aren't air-tight long enough to kill bugs. However, #1 PETE *is* airtight (for at least a year, which is far more than long enough to kill bugs), and usable for food storage.

William Bronson wrote:I'm considering  using sections of corrugated black drain pipe.

ROFL; we had the same idea!

For floor, I was thinking just a 4' by 4' sheet plastic, for $10, with two or so holes drilled in the bottom. 4'x4' would get me over 150 "floors" to the pots, which could just rest on flaps and easily be pushed upwards to remove plants when it's time to plant them outdoors.


I was thinking something like this:

Here is what I have had to try lately.  I was given a large bunch of these.  The tree pots are 3x3x8 (pot # 38 and tray # TR6)  and the tray to hold them is supposed to 25 but with these and crowding it I can get 36 of them in a tray.  Notice the bottom of the pot is nearly open.  I use these in indoor tray situation I have been cutting small squares of latch hook rug plastic mesh to drop in the bottom and hold the soil in.  Come planting time a simple stick pushes the soil ball out along with the small square which is recovered to reuse with the pot.  The I have been using these pots 3 years with no sign of deterioration so they should do at least 4 years.  The pots are well ridged to try to force roots down instead of spiraling and the bottom fairly well air prunes.

trays(select option TR6)

tree pot name 38.

I can’t bring myself to buy anything plastic if at all possible, but will re-use plastic already in the system. For round containers I like the 24 oz yoghurt tubs that are about 4” diameter and 4” tall. For square, I use cardboard milk cartons- quart size is about 3” square and half gallon about 4”. What’s great about them is they are still nearly 8” tall with the top cut off, which allows for a deeper root system to develop. I don’t buy yoghurt or milk in containers, but know people who do, and can be persuaded to save them for me in exchange for plants or veggies later on. All of these get holes drilled into the side about 1/2” off the bottom, which assures water is always available in the base, which gets a layer of gravel. The yoghurt cups last several years, the milk cartons tend to get soggy and rot after 1 use. I have a short season so everything gets transplanted to a larger container at least once. I still have some root crowding, but it’s not as bad as what you’d get from a nursery. Tomatoes like to be transplanted deeper to develop more roots along the stem, so this is never a problem with them anyway.
I have experimented with soil blocking, which nicely eliminates root bound seedlings, but can be labor intensive because you have to be very aware of how quickly the soil at the perimeter dries out. I’ve also never seen a tool to make 4” blocks, though I’m sure one could be found or custom made.

Just wanted to say I've researched and it seems that Polypropylene (PP [5]) is the safest plastic.

I've tried using those peat pots but they never disintegrate so it rootbounds the plants.

Bootstrap farmer is the only source of polypropylene flats and trays I've found. But the dollar store has PP trays meant for containers that are way less expensive.

I've noticed the black pods do tend to hear up in the sunlight and I'm curious to hear other solutions.

I also collect and use the 24 oz yogurt containers for tomatoes. I drill a hole in the bottom for drainage. Think is was Judy that puts gravel in the bottom, which is a great idea. I fill the pot half way with soil and plant a seedling. Ten put the lid on. My lids are clear and I have poked a hole in it to let the air circulate. As the tomato gets taller I add more soil, eventually removing the lid. This lets me start the tomatoes much earlier. The plants have a good root system and I get an earlier harvest.

I have also planted directly in the garden and covered the seed with a clear soda bottle. I cut the bottom off at about the line (most plastic bottles have an indentation around the bottom). I take the cap off and walk away. This works with cold crops that like warm sow to germinate.

I garden in zone 8.   I just read this article by Trudi davidoff.

http://www.wintersown.org/wseo1/how_to_winter_sow.html

It was Julie, not Judy who suggested gravel in the bottom of the yogurt containers.

Julie Reed wrote:I can’t bring myself to buy anything plastic if at all possible, but will re-use plastic already in the system. For round containers I like the 24 oz yoghurt tubs that are about 4” diameter and 4” tall.

We used to use the milk carton bottoms as well, and they're a great size, durable enough, and rip easily off the seedling for transplanting. We've since moved to litre bags of milk (oh for a cow). Has anyone considered using large trays I.e. either wood with a drop-floor, or cardboard box with cardboard dividers? The former would have more legs over time but the latter would tear away leaving the root balls for transplanting.

Ever thought about using a soil blocker?
https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/soil-blocking/hand-held-1-soil-blocker-9016.html?cgid=soil-block-makers#start=1&sz=18
I have the 4 blocker but that only does a 2”x2” This one however only does 1 at a time, but it does a 4”x4” (out of stock but link provided for concept)
You start them in the 2x2, and graduate them to a 4x4.
Currently reusing a paper box just as a means of holding the dirt in from all the cubes, it won’t stand the test of time obviously but I plan on making a few boxes for them later. It’s my 1st year of use, so not entirely sure how well they work yet.

Have you tried making these origami newspaper seed starters? I think I’ll give it a go this year.

https://youtu.be/7dlGQP81yfo

I saw this posting and just took a very few minutes to browse web sites and a couple of catalogs to obtain some info for comparisons. Don't be afraid to use your Browsers! I simply typed in the following:  4" square reusable seeding containers   to get most of these results. IF you want a great CATALOG of greenhouse and/or growing supplies see the last paragraph for info on calling or faxing for their current "Greenhouse Supply" catalog. The price on the front of mine is $2.75 but got it in the mail free as I have been a customer in the past.


Amazon:     12 Pack Small 3.90 Inch Plastic Flower Pots for Plants,Cutting,Seedlings,Black Nursery Pot Square Starter Pots with Saucer (Plants Not Included)     $9.99=  
Greenhouse Megastore:  4” sq X 3.5” tall  -  15/Pack  $3.39
Growers Solution:   4” square  Sold as Each     $0.25
Amazon:  Kinglake 4” Plastic Plants Nursery Pot/Pots Seedlings Flower Plant Container Seed Starting Pots  -  100 Pcs    $12.09
WalMart:   DecorX - Plastic Plant Nursery Pots  -  8 Pcs   $20.16
WalMart:   UHUSE  -  Flower Plant Plastic Nursery Pot Seed Starting  0 100 Pcs   $23.49
Johnny’s Selected Seeds:  Square Plastic Pots  3 ½” Sq 3 ½” Height  18 Pack   $8.17
Burpee:  PotMaker – Make pots from old newspapers – Hardwood Mold    $19.95

ORDER - CATALOG only:  E&R Seed, LLC  1356 E 200 S, Monroe, Indiana  46772. This is run by Amish, so no Web Site. Phone 260-692-6827   -   Fax 260-692-6576     Ask for the current Greenhouse Supply CATALOG.  I’ve personally purchased from E&R and had good luck with their products. This catalog is an excellent source for just about everything concerning from starting seeds to greenhouse structures.

I’m considering making silicone pots.
Any thoughts on this?

https://specialtyresin.com/product/cast-mold-platinum-food-grade/?attribute_pa_cast-a-mold-platinum=cam-plat-32oz&utm_source=Google%20Shopping&utm_campaign=Google%20Shopping%20Feed&utm_medium=cpc&utm_term=3021&gclid=CjwKCAiAuoqABhAsEiwAdSkVVItW-oEg8pMC7btUqXAK84PNmFRD4SpJ7BLlcwOOSn-Gy9CzWlpSkRoCrfAQAvD_BwE

I am considering using a pot as a mold to make silicone pots.

https://specialtyresin.com/product/cast-mold-platinum-food-grade/?attribute_pa_cast-a-mold-platinum=cam-plat-32oz&utm_source=Google%20Shopping&utm_campaign=Google%20Shopping%20Feed&utm_medium=cpc&utm_term=3021&gclid=CjwKCAiAuoqABhAsEiwAdSkVVItW-oEg8pMC7btUqXAK84PNmFRD4SpJ7BLlcwOOSn-Gy9CzWlpSkRoCrfAQAvD_BwE


Any ideas?

Stephan Leaf wrote:

This one however only does 1 at a time, but it does a 4”x4” (out of stock but link provided for concept)
You start them in the 2x2, and graduate them to a 4x4.  

Please report back with your experiences with the 4"x4". I have not tried getting any of the soil blockers because in my wet, cool, spring, my plants have to be larger to out-compete the slugs and 2"x2" of soil simply isn't enough - when roots hit the bottom that quickly, they often think it's time to bolt. I hadn't seen a 4"x4" blocker before.

Jesse Glessner wrote:I saw this posting and just took a very few minutes to browse web sites and a couple of catalogs to obtain some info for comparisons. Don't be afraid to use your Browsers! I simply typed in the following:  4" square reusable seeding containers   to get most of these results.

The issue is, many of them *say* reusable, but are made out of cheap plastic that only lasts two or three years and cracks easily.

Some even say, "reusable and recyclable" - but if they are oh so reusable, why would I need to recycle them? =P

I ended up getting these ones, because they looked sturdy. They've since arrived, and flexing them with my hands make me happy with the purchase, but it remains to be seen how many years they last. I suspect I might get ten years out of them, unless they get brittle in the sun.

Stephen Leaf wrote:Ever thought about using a soil blocker?
https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/soil-blocking/hand-held-1-soil-blocker-9016.html?cgid=soil-block-makers#start=1&sz=18
I have the 4 blocker but that only does a 2”x2” This one however only does 1 at a time, but it does a 4”x4” (out of stock but link provided for concept)

I've considered it, and I love the concept! I am a little concerned the dirt would dissolve, especially with bottom watering - but I have no experience with them, so perhaps my fear is unfounded.

You start them in the 2x2, and graduate them to a 4x4.

I don't bother starting things in small pots just to move it to a larger pot. It just seems like more work, potentially damaging plants in the process. I start things in 4" and keep it that way until I plant them 8 weeks later.

I would try dumpster-diving behind the nearest nurseries, home centers, or anywhere else that sells plants. Granted, this isn't going to help you right now, but as the year progresses lots of 4" starter edibles and ornamentals that don't survive will get tossed out. I've acquired so many 4" pots that way, I had to Freecycle a big stack of them last year.

Melissa Bee wrote:I would try dumpster-diving behind the nearest nurseries, home centers, or anywhere else that sells plants. Granted, this isn't going to help you right now, but as the year progresses lots of 4" starter edibles and ornamentals that don't survive will get tossed out. I've acquired so many 4" pots that way, I had to Freecycle a big stack of them last year.

Fantastic idea!

Two years ago, I did the exact opposite: I had about 100 pots of various sizes (from quart pots all the way up to five gallon pots) to a local nursery that I'm on friendly terms with. They are too big for seed-starting though.

Im going to start seeds in an old refrigerator in large bamboo culm s that I cut in 4inch pieces. I'll lay an old storm window over the top during day --remove and close the door at night. This is first time I,ve done this but results should be interesting.

Jamin Grey wrote:

Jesse Glessner wrote:I saw this posting and just took a very few minutes to browse web sites and a couple of catalogs to obtain some info for comparisons. Don't be afraid to use your Browsers! I simply typed in the following:  4" square reusable seeding containers   to get most of these results.

The issue is, many of them *say* reusable, but are made out of cheap plastic that only lasts two or three years and cracks easily.

Some even say, "reusable and recyclable" - but if they are oh so reusable, why would I need to recycle them? =P

I agree that those you have purchased look much better than the cheaper pots and should last several years.

I saw that one person is going to try silicone, but I have doubts that those will work well. They have silicone baking pans and when I've seen on TV people trying to get their goods out of those they are peeled off because the silicone is "sticky" and the soil core having roots grown around it would expand putting pressure on the silicone. ALSO, I've worked with and around a lot of silicone and I would NEVER use silicone for anything that goes into an oven. I don't care what they say, it all out-gases and you can bet your life it goes into the food. Remember that the old TEFLON pans were also supposed to be SAFE and many people later found out that they were NOT safe at all?

Any way, I just thought I'd give people links to go search for what they wanted/needed and could afford in the way of seeding pots.

Owen Rogers wrote:Im going to start seeds in an old refrigerator in large bamboo culm s that I cut in 4inch pieces. I'll lay an old storm window over the top during day --remove and close the door at night. This is first time I,ve done this but results should be interesting.

1. What's the inside diameter of the culms?  
2. Do you plan on sliding the seedling out, or planting it culm and all and just expect that it will stick roots out the bottom?
3. If you're sliding the plants out, do you intend to save the culms and use them for several years?

Yes, please report back whether it works or not - if one had a variety with large diameter culms, this would certainly be a great way to get away from plastic!

I don't think any of my bamboo will grow to a large enough diameter - we're not really in the best eco-system for it, but I still find lots of uses for the varieties I grow.

I have a several varieties  of bamboo different size culms. Largest is about 3 inch. I won't reuse them. After seed come up I might experiment and split one side of culm to give them room to expand. Or just split both sides. I also have a cast iron bamboo splitter  that I'll play with  too. Got it off amazon for about $20.

Jesse Glessner wrote:ALSO, I've worked with and around a lot of silicone and I would NEVER use silicone for anything that goes into an oven. I don't care what they say, it all out-gases and you can bet your life it goes into the food. Remember that the old TEFLON pans were also supposed to be SAFE and many people later found out that they were NOT safe at all?

I still remember what the Teflon pan manufacturers said, I think just two years ago, "There is absolutely no evidence Teflon causes any harm to humans, but we're no longer going to sell pans using teflon." Yea, sure mate. I bet a whole armada of lawyers reviewed that sentence before sending it out. =P

Hello everyone! Long time reader but first time poster here
Please forgive me if this has already been considered, but I’ve been reading Linda Woodrow’s Book and she talks about re-using 2 litre plastic milk bottles. The ones we have here (in Australia) are about 4 inches by 4 inches wide. She cuts off the top about where the handle starts, AND the bottom, so she has a square shaped cylinder. Then she seeds into these (sitting in a wooden flat which keeps the soil in the bottom but allows drainage), and then when the plants are ready to go out she makes the hole as deep as the ‘pot’, sits the pot in the hole, and then slides the plant into the hole through the BOTTOM of the pot. She then leaves the pot at ground level (pressed in a bit so it doesn’t fall over) and that kind of acts as a little protective covering for the plant for a few days while it settles in.
I haven’t tried this yet myself but am hoping to next
autumn if I can get set up in time
Apologies if you’ve already tried this though!

Wonderful ideas here!  Led me down some pot making rabbit holes.  Came out with another idea for making square grow bags from landscape fabric.  But I'm sure you could use old cotton fabric if you wanted it compostable.  Maybe some old bed sheets?

https://www.youtube.com/watch?v=vq3aBghgGfo

Not permanent but I  used toilet paper tubes for seed starting a bit last winter, folding the bottoms in and filling with soil. They can be planted as is in the garden or pot or with the bottom in folded so the roots can get out more easily. I plan to do it again this year. I've been saving the plain brown grey tubes not the white ones.

Melissa Bee wrote:
I would try dumpster-diving behind the nearest nurseries, home centers, or anywhere else that sells plants. Granted, this isn't going to help you right now, but as the year progresses lots of 4" starter edibles and ornamentals that don't survive will get tossed out. I've acquired so many 4" pots that way, I had to Freecycle a big stack of them last year.

If you live in an area that has any large commercial properties, like a hospital, office complex or senior home, as examples, they usually have professional landscaping done. If you can determine the day flowers are planted in the spring, the nursery people doing the work often toss all the containers. Very few big nurseries actually grow anything, they just maintain the plants they buy wholesale. So, they will never re-use those pots. I once got hundreds in one weekend, and still have quite a few of those after many years of use.

Jay Angler wrote:Stephan Leaf wrote:

This one however only does 1 at a time, but it does a 4”x4” (out of stock but link provided for concept)
You start them in the 2x2, and graduate them to a 4x4.  

Please report back with your experiences with the 4"x4". I have not tried getting any of the soil blockers because in my wet, cool, spring, my plants have to be larger to out-compete the slugs and 2"x2" of soil simply isn't enough - when roots hit the bottom that quickly, they often think it's time to bolt. I hadn't seen a 4"x4" blocker before.

Sadly I don’t have the 4x4. I’m umm.. ahem, cheap. So I thought I’d see about trying to get by with a 2x2 this year, see how things run. As for the fears of these, Some are going decently, my kale has sprouted already but like mentioned they do tend to deteriorate, or in 2 cases, because I had so gingerly closed up the tops and because my watering can isn’t exactly the definition of light or gentle with its watering, I found 2 seeds that had sprouted next to their blocks rather than within it! Oops! Can’t complain too much about the little leaky thing tho, I got it free from a neighbor.

I’ll still try to respond back when it comes time to plant how things go. Much of what I’m doing this year is all experimental. I’m way over my head in seeds (the wife and I had way too much fun with the ordering....) and I’ve not had an actual garden since I was a kid due to the lack of a backyard. Dabbled in a potted garden for a few years tho.
Nice weather tomorrow and I can’t wait to get out and get more plots ready for planting. Would have loved to do a no-dig, but my compost is only 3-4 months old and a bit modest in size and remember I’m cheap! My rock path is steadily growing! We grow good rocks here in Missouri!

Stephen Leaf wrote:

My rock path is steadily growing! We grow good rocks here in Missouri!

Oh, I know *all* about that. We grow big rocks, little rocks, bed rocks and who knows what other category of "rocks". We're so good at it that Hubby bought me a rock drill and feathers and irons and we spent a bunch of time turning big rocks into smaller rocks until he decided to buy a tractor to at least shift them out of our way!

I'll echo props for the soil blockers from Johnny's.  I have the tiny size 1/2" cubes, 2" cubes, and 4" cubes.  Basically it's a mold that makes mud pies in all those sizes.  Mud pies are fun!  Instead of hours of scrounging/sorting/dealing with plastic pots!  My tomatoes and giant basil plants do fine in the 4" cubes. They grow in a tray where I can water from the bottom, or spray them with a hose wand.  Initial investment was about $200 but I am not having to store crumbling piles of plastic pots.  I will say it was awkward to sell plant starts in soil blocks.  Few people were prepared to carry one away, and the success of the plants depends on early planting.  

I now use mostly my own composted loam to make soil blocks--and horse manure (thanks, ponies).  Minimal need for bought peat or perlite.  I use all sizes frequently, and the tiny size helps me get the most out of every seed, and evaluate seedling quality early on.

I will say it was awkward to sell plant starts in soil blocks.  Few people were prepared to carry one away, and the success of the plants depends on early planting.  

My local grocery store recycles all their cardboard, at a loss, as they have to bale it but don’t get paid for it. They are more than happy to give boxes away. I often grab the heavy duty ones they get produce in to use for my plants. You might be able to use something like that for people to carry soil block plants in?