Ok - just to be clear, I never say anything disparaging about SWCs. They fill a need for those that can't or don't want to get out and water mature plantings every 2-3 days. For my purposes, I have hundreds of plants on varying watering schedules (yes, I water on a schedule because the soils I use easily allow me to do that), so I have to drag the hose around the entire circuit daily anyway, so I just prefer to water from the top.

The gritty mix isn't suitable for SWCs. It's designed to eliminate perched water and it won't wick sufficiently to lift water high enough to moisten the soil. Let me reconsider that for a second - if you are using a plastic vapor barrier on top of the soil, it's hard to say what may or may not be suitable. Water vapor condenses on the vapor barrier and drips back into the soil, wetting the top of the soil with distilled water. I've made an assumption that I'm not 100% sure of, so if anyone ever experiments with the gritty mix in a long term container, please report. I think though, that it wouldn't be practical. It's more expensive and heavier than more organic soils (like the 5:1:1 mix), and most SWC plantings are seasonal things. I'm afraid that you might have a salt accumulation that will raise TDS/EC to levels too high over the long term, but that would be true of any soil.

If you're including pine bark fines (PBF) in your soil, the mix %s that will work best will vary according to the size of the PBFs. If the bark is very fine, you might be able to use 5:1:1-2, bark:peat:perlite, but if the bark is coarser, something like 4:2-3:1-2 will probably give you closer to the 'wickability' you're looking for. Most often, people start with a quality potting soil and add PBFs and a small amount of perlite until they get the wicking action they want. It is, however, much less expensive to forgo the use of the potting soil in favor of peat. It's much less expensive if you buy your peat/perlite in large bales/bags and add your own lime. You end up with virtually the same product. I do understand the convenience factor, but it's hard to understand that, from the perspective of cost, why anyone would buy a commercial soil when all they are is peat/perlite/lime and maybe a wetting agent. They're at least twice what you can make the soils for yourself.

A drip irrigation system is ok, but any failure is often a disaster in terms of lost plantings or set-backs.

You know when you have watered a conventional container sufficiently when water starts flowing from the drain hole after watering with a gentle stream of water that only wets the soil w/o splashing water on stems/foliage - assuming your chosen soil allows watering to container capacity (saturated soil) w/o risking root rot. The water that flows out of the drain holes carries accumulating salts with it.

You can use either the 5:1:1 or gritty mix in SB towers, but DO make provisions for a wick. The top will dry well before the bottom, so it's important to eliminate any sogginess at the bottom of the tower. If you make one, stop back and we can talk about how you can make a 'drip leg', similar in function to the connection strategy they use on appliances connected to natural gas. It will help you a LOT.

A regular container doesn't need to be on supports unless you're using a wick. Then, the wick either needs to be dangling below the container and not touching the effluent, or it needs to be touching the soil so the earth can serve as a giant extension of the wick. Setting the containers directly on the soil so there is good hydraulic continuity between the soil in the container and the soil in the earth changes how water behaves dramatically. You can then use a heavier soil than you could in a conventional container because hydrologically speaking you've turned a conventional container into a small raised bed.

One drain hole is as good at draining a container as 100. I would use a 1/2" hole that I melted in a corner of the container at it's deepest point. I would make sore that the hole is situated so water tends to run toward the hole. That's where the wick would go, too. Plants don't care if it takes 1 minute or 3 minutes for the soil to stop draining ...... so 1 hole is sufficient, but if you want more ..... go for it. I only use 1 hole in all my containers (stronger) unless they came with more, and I cover them with Fiberglas insect screening or a plastic mesh used for needlepoint projects (craft/hobby store - cheap).

Almost everyone here will offer tons of encouragement, Don. If you have questions, it's unlikely you can't get them answered by one or more of the more knowledgeable gardeners here. As you sort through any answers/advice, if you focus on the positive help and consensus directed toward what you CAN do, instead of what you can't or shouldn't do, you won't go wrong.

Best luck. I'll watch for your questions & offer help/comments as I can.

Al

Al, first off let me apologize for my misstatement about the SWC's. The way I have read some post of yours I got the impression you were asking why would someone want to use them with your mixes. Kind of like why spend more money than you need to.

I should have noted that what I plan to do is lay down heavy tarp which I think is way too expensive, or 4 to 6 mil plastic, then cardboard on top of that. Then set the totes/5 gallon buckets on top of that, then mulch around the containers.

I am gonna go with the 5-1-1 mix in my containers.

Thanks again Al I really appreciate.

I will start another thread on the strawberry towers with the dimensions and how I plan ot make them.