What volume of soil do you need the containers to hold?

Al

I was hoping you were lurking around Al. Thanks for the interest.

I'm looking for around 3 gallons, or about .4 cubic feet. If I did my math correctly (not my strong suit), 3 gallons volume would equal approximately a 8.5"W by 12"H cylindrical container. Of course you could fudge the dimentions around to come up with all kinds of sizes but considering my limited table space I kind of need something not very wide.

An approximate circumference for a 8.5"W container would be a felt strip about 26.5" long. So in theory a 3' X 3' piece of felt could make the sides and bottom of three 3 gallon containers. Assuming of course all this math is correct, which it may not be.

Hello Brandon,

I kind of a small unconfirmed diy air prunning root control situation (totally accidental) going but with good on-going result. I say unconfirmed (success) because while the top growth of my Pai Tsai (leafy Chinese cabbage) looks healthy, prolific (as well as with given space), and tasts great and where the air root prunning principles would apply in this accidental setup, I haven't digged up the roots to check the growth and condition of the roots, although the "main stem connecting to the roots" on each leafy cabbage at the soil line looks very sturdy and strong, to confirm it is being air prunned to qualify. And even if the roots are being air prunned, I would have to repeat the setup and reproduce the results to qualify it as a possible root control alternative.

Here is my setup:
My vegetables are growing in two layers of fiberglass window screen material and placed in a small round old beat up decorative metal wicker planter (10" wide and shallow and almost no wicker left to hold shape) and lined with a layer of cut open and SCORED/STRIPPED white shopping bag without ink or printing on the plastic.

I'm guessing a double or triple window screen setup can also be used with or w/o a thin exterior white or black plastic garbage bag for a larger setup or a hanging grow bag setup.

What do you think?

Hey Legacy, thanks for your experience. I actually never thought about the window screen thing. Sounds like it could work very well also. Soil spilling out of the window screen wouldn't be a problem since I'm using a mix based off of 'Al's Mix' that has gotten me off to a wonderful new start on container gardening.

Let us know if you have continued success and if you're able to reproduce that success!

Thanks again!
-Brandon.

FYI if it will help: I'm using a soilless mix as well in this 2x window screen setup. It is closer to a rooting mix but not quite than a potting mix but with organic mulch.

Ya know, many websites I've seen suggest using a more dense potting medium when using air pruning containers. They say since more of the root mass is exposed to air (the sides and the top vs just the top) the medium tends to dry out faster so stagnation is not as much an issue.

Sounds reasonable to me, but now that I've had such success with Al's Mix and have seen what roots can do in the proper medium I will find it hard to go back to anything else.

I was giving relevant context to anyone interested since you raised the potting mix issue. It was not to suggest anyone should change, NOT use Al's Mix, or use some other mix :)

Thanks and you have a point about the essential advantages of being able to use heavier rich soils (heavier than Al's mix as well) in root control bags for long-term planting (but a light soilless mix will work and last as well). The best choice of mix will ultimately vary and rest on a gardener's objective, the requirements of a plant, and the regional climate and microclimate really. Keep in mind that I started this setup (a light mix in 2x windows screen) not for root control or prunning but to utilize available resources while applying proven horticultural principles, and it was done before I read about air prunning.

I will probably test on some other plants next, but I have spring bulbs, peonies, sweet peas, and poppies to worry about right now. Let us know how your creative ideas work out, too.

'sup, Brandon? Thanks for the vote of confidence (soil). ;o) I'm always lurking around here. I think I just commented somewhere about containers that self-prune roots - probably here. That makes the most sense.

Before I get too far, let me ask if you ever considered using the mesh baskets that are used for aquatic plants? I use those, they're reusable, and I also often use containers with perforated or slotted sides from the dollar store. If you nix that idea, I have some other thoughts.

If you decide to go the screen route, let me know. I own a glass company and get screen in 100 foot rolls, width in 6" increments, alum & Fiberglas, and can get it to you at my cost (prolly around $.05/ sq ft plus shipping).

Al

Just thought of something. I believe these reusable root bags suppose to last long-term (and 5 years for peonies) and so with the reduction also in the costs of replacing potting soil and/or potting mix for say 5 years, may be the purchase is quite economical and cost effective. I'll leave the calculations to someone else.

Again, thanks for all your input Legacy. I didn't think about the long term use and savings in using those bags, plus as you mentioned the stability of a good potting mix. Maybe you're right. Those bags may be actually MORE cost effective in the long run. I'll have to look into them more.

I have two major issues that have always plagued me in any hobbies I've had:
1) I'm super cheap and always look for the least expensive way out of a situation.
2) I tend to over-think things on many occasions.

Perhaps this is one of those times. My poor wife has been very good about putting up with me in those areas. If she knew what I was thinking about, she'd tell me to bite the bullet and buy the commercially available stuff :)

Al, your kind and generous offer is humbly appreciated. I will seriously consider it and let you know privately.

BTW, I'm still using that bag of "Al's Succulent Mix" potting medium that you sent me several months ago. It has been working great! I repotted a few Lithops, Haworthias, and a Sansevieria leaf cutting I had propagated. All are doing great and in no fear of over-watering. Thanks again!

I think I'm more inclined to go with Legacy's suggestion of the window screen instead of the felt. I'm theorizing that the "felt" used in the commercially available bags is special treated for longevity in a potentially rot-inducing environment. The stuff at the fabric store most likely is not as durable. Though there's only one way to tell for sure...

Both of you have given me much food for thought. Any further comments are most welcome.

Thanks again!
-Brandon

Lol - NOW I remember why your name was so familiar. I forgot I sent you soil. I have lots of interactions with forum folk & it's hard to keep them all straight. ;o) I'm soo glad you liked it.

No additional input I guess. Looks like you have it covered unless you have any questions you think I could help with. Good luck, Brandon.

Al

More diy root bag inspirational ideas to test:
1. Recycle old panty hose or sock liners for campers and hikers (for mini and designer hanging planters)
2. Sew microfiber squares together (or synthetic dish or cleaning towels)
3. Recycle and sew scraps made of old expensive gortex (the athelet and climber in me) and athletic or outdoors clothing made of breathable synthetic fabric
4. Sew a bag made of nylon shading material or tennis court type wind screen (sold in garden centers as well as Walmart). Stores usually sell the sewing kits with the roll, too.
5. Recycle and plant in an open inverted old umbrella. This is not a root-control bag but more a container with a central plant support and some holes or scoring will provide proper drainage and aeration.
6. Recycle large fruit/rice bags (tarp-like material)

The wind/shade screen can also be used as a liner in a container or as a sculpture of any shape made of chicken wire, a milk crate, or stackable plastic bins.

Monofilament (fishing line) in sporting goods or framing shops can be used for sewing any of the materials mentioned in addition to the various sewing kits that can be purchased with the wind/shade screen.

Legacy, don't you ever sleep? :)

You had some excellent ideas. #1 sounded especially easy to play with. Right on with the fish line to sew the screen together. I had been wondering about what to use to join the sides and the bottom.

At this point, before I commit myself to anything major, I will try some of the window screen and make a few pots. I'll post back with my success or failure to let you guys know what happened.

Again, thanks for the great help and excellent ideas both of you!
-Brandon.

Dear Brandon,

I don't know how far you want to take this project, but in order to ensure a diy root control bag to be as competitve as the marketed ones in functionality in controlling and maintaing root temperature in the summer and repotting less (long-term planting required by certain plants) in addition to the benefit of air root prunning, top soil or a heavier and more permanent fertile soilless mix and not a light soilless potting mix favored by you has to be used.

One layer of window screen should be sufficient for air pruning to take place. However, I'm wondering if two layers of window screen may offer an added durability (and moisture retention) without complicating the equation or the ease of making one. I'm sure repair patches can always be a backup option, but if you have the resources, time, and inclination, you may also want to test two/three plants of each - one layer or two layers of window screens, to see if there are differences in functionality and durability.

Best wishes

Monofilament fishing line can't handle sunlight for long. It looses strenght pretty fast-gets brittle etc.
Not good for long term use.
It would suck if you watered one day and your seams split...

Now the spectra type lines are allmost indestructable-small diameter,high breaking point for their diameter.
The stuffs like kevilar,bullet proof.

Find a tackleshop that re spools line on fishing reels.Might find a goldmine full of spectra.
Most guys reverse it on their reels when it gets old so the middle is a lot of time like new but too short to use for fishing.It would be perfect for your use as sewing thread.

Legacy, thanks for the interest on this subject and all your advice. It is appreciated. About your concern for using a heavier soil mix: you're probably right. The more I think about it the more I wonder if the basic "Al's Mix" would dry out too fast even with daily waterings. But there's only one way to tell for sure.

Concerning the structural integrity of the container with only one layer of screen: I had already begun to question that as well. Two layers would definitely up the ante in terms of support, especially for containers larger than 3 gallons (which if this experiment is successful I will need many of them much larger than this size such as >10gal). 2 screens would probably work but I was leaning more towards a layer of hardware cloth with 1/4" holes. I've used that stuff around the house lately and it seems to hold up to abuse fairly well. Alas I don't have any left, but it's cheap enough and available everywhere.

Smokemaster, thanks for the info about the fishing line. I hope you're not right about it becoming brittle in a short time, but I'm sure you are correct. I'll look for that Spectra type line sometime soon.

Yesterday I picked up some aluminum screen and monofilament fishing line (before I read smokemaster's suggestion). Construction will begin today.

I'll post back with some pics of the finished product.

Thanks again everyone!

This is quite an old thread but here goes.........

I'm going to use a plastic laundry basket lined with 2 layers of fiberglass window screen fabric. I will use regular potting soil with added fertilizer (Espoma GardenTone) at a rate of 2 cups per 2cuft. The basket will hold just under 2cuft of potting soil. BTW the potting 'soil' I will be using does not have any 'soil' in it. I also may use ProMix BX. Three seed potato in each basket. In Virginia we can plant potato in June for late fall harvest. Something will be mixed into the potting soil to help with moisture retention. Thinking about coco coir, cocoa hulls or vermiculite. I have never done this but I got these seed potato from Lowes for almost no money (75% off) so it won't hurt anything to try. I will do a photo diary and post results. As for cost I am looking at $8 for the soil, $2-$4 for the laundry basket and I already have the screen so can not remember the cost. I could easily sew the screen and make some bags but if the bags broke apart when full I would be quite upset.

Film at 11.............

DL