You may want to read my post regarding this very thing.

Donna H.

Here is a link that might be useful: My First Year With SWC's-Notes From A Complete Beginner

Donna, I read your posts with great appreciation.
In regards to your tomatoes in 5 gal SWC, you said
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While the PH on the tomatoes was a decent 6.5 (Ideal  6.4-6.8), I note that the soil moisture at 2" was only 2 and at the deepest level was 7. This confirms that with such a complex root structure, wicking upward against gravity is definitely an issue in keeping the plant sufficiently hydrated.
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I was kind of looking for a little more input on this. Maybe a bit "wetter" mix when in a taller container?
I am coming to think tomatoes have a terrific need for water. A small bush tomato I have in a 12 gal tub takes a gal a day with normal temp outside.
Kenny

I had requested input from those that had more experience with SWC's because I was having such mixed results as you probably read. The tomatoes were specifically problematic as I said here:

"...Due to the problems with the tomatoes, IÂm thinking that they should be placed into shallower, but larger containers like the 10-gal Rubbermaid Totes. Considering that the inventor of the commercially market EB specifically designed it to accommodate two tomato plants (within its 29L x 14W x 11H outside dimensions) the success of plants grown in this sized container speaks to this containers ability to provide ample room for the root system as well as being able to deliver nutrients and hydration.

10-gal Rubbermaid Totes dimensions are 24L x 16W x 9H. Since the soil depth for the commercial EB unit is approx 8", using a dual 10-gal system for ONE plant may work just as well, if not better than the commercial EB."

I'm still thinking that the depth of the soil was indeed the problem. The tomato plants will continue to suck as much water as they can I found, even to the extent that the roots are constantly soaked. I don't believe that tomatoes really enjoy being that wet, but the hydration is driven by the complex root structure and that wet state can certainly be exacerbated by the potting mix. Ughh!

I have been following a few gardening blogs and Green Roof Growers has a great one with SWC's (SIP's as they call them). This year, they decided that the tomatoes needed a larger water reservoir so they purchased 8-gallon buckets and grew in them. They had a terrible growing year...didn't we all...and their tomatoes did horribly. Looking at the photos, I thought they looked quite a bit like mine...rather spindly and not a lot of lush green growth. They posted that they weren't sure what the problem was, but maybe after they pull their plants they'll discover that the tomatoes were sucking too much water. Just a thought...

As far as the mix goes, I'm going to try a little different mix in mine next year with more bark fines and less peat. I posted the question about "basic mixes" at the link below and got a little feedback, but I'm still going to experiment with Al's suggestion:

"7 bark fines
2 peat
1 perlite
1 vermiculite
1 tbsp garden lime/gallon
would probably be a very good mix for SWCs.

For a fertilizer program, I would use something with a 3:1:2 ratio like MG 24-8-16 for the first month after potting, then switch to a 1:2:2 ratio like 5-10-10 or even a 1:1:1 blend such as the 14-14-14 you're using. Please be sure your plants are getting the secondary macronutrients and all the minors. Ca and Mg are particularly important."

Does this help?

Donna H.

Here is a link that might be useful: Best 'Basic' Mix For Vegetable Growing

colokid

The 5-gallon SW buckets are fine for determinate tomatoes. I've used them for years, though the indeterminates did not do nearly as well, filling the entire soil chamber with roots and requiring total fillup 2-3 times a day in mid-summer. I had much better production and health of indeterminates in the garden. OTOH, you'll find many who have successfully grown indeterminates in those 5-gallon SW buckets. It's purely a matter of preference, and in my case, it takes more effort to keep them healthy and supported than I'm willing to expend!

I used a 4-inch wicking chamber in the 5-gal. self-waterers, and that works great in mine. However, I have read posts where growers say that size wicking chamber for some soil mixes makes the soil too moist.

But here I deviate from the generally-recommended procedures, so my results are different. I leave the top of the soil uncovered, though I will put an organic mulch, not plastic, on it to keep the soil moist. I also provide for soil aeration with a perforated and screened PVC pipe run horizontally through the entire setup. I locate the aeration pipe about 2 inches above the wicking chamber, and it extends slightly beyond both sides. Thus, the bottom of the soil chamber doesn't need to have holes in it. This is probably why I don't have problems with soil that is too moist. With the "aeration device" running through the bottom of the soil chamber and the open soil-surface, I feel secure that the air-flow through the soil is more than adequate and the soil is not too wet.

So your setup probably affects the way the soil is moistened with a 4-inch wicking chamber. When the surface of the soil is covered with a plastic mulch-barrier, that seems to be the condition where the soil is sometimes more than optimally moist.

All you can do is construct your self-waterers as you see fit and see how they do! But five gallon buckets are certainly not too deep for determinate tomatoes.

I'm kind of thinking that the 5 gal double made are like the single made with a couple of inches more mix at the top which tends to be dryer-all most like a mulch. The extra volume has got to have a little benefit I think. Any way I appreciate any and all comments. Evan tho my mind was pretty well made up on how I was going to do it, the doubled up ones. Since I had enough buckets.
Be nice if there was a bucket a little bigger around and a little shorter...say 5 to 8 gal, and were given away free....
Got to go look and see if i can find my 4 inch hole saw...have a good day every body.
KennyP

colokid,

I tried indeterminate tomatoes once in a 5 gallon bucket with a fast draining mix, no plastic mulch. Interestingly once the plant was big it always wilted in mid-day even though the reservoir was full. The top inch was dry but below that the mix was damp. As soon as I gave it a top watering in mid-day it recovered.

My conclusion was that the mix to too porous and the roots couldn't make enough contact with the mix to drink fast enough in hot weather.

So I'd say you probably need some peat in the mix, plastic mulch for a 5 gallon big tomato plant and some sort of automatic watering setup. But every climate is different

emgardener, I might guess that there was not enough roots to support the bigger plant up above. One of the reasons I am using the double bucket, is to try for a little more capacity.
I know there are many better mixes, but to keep it simple. I will use potting mix with perlite added. Thats normally a little wet.
I grew a couple last winter in tubs, before I was "educated", with straight MG potting mix. Biggest problem was they grew up above the light by 3 feet and hit the ceiling. One was a rutger and i forgot what the other one was. Spent most of my time learning about lights.
KennyP