I don't use SWC's, but it's my understanding that they need a higher percentage of peat in order to wick water up to the soil surface. The 5-1-1 mix is better for pots that will be top watered, but in the case of SWC's, a small sacrifice has to be made for the convenience of a SWC.

Exactly what Penfold wrote.

Josh

Ditto for the above, only you will be make a large sacrifice for the convenience of SWCs.

I've used both types of mixes in SWCs and the fast draining ones don't work well.

Since you are doing so many, you might want to use the 5:1:1 in one bucket and see how it goes just for the experience. You can always resort to top watering later on if needed.

Not much I could add that you guys didn't already nail down. ;-)

Al

Not much I can add either. Great job nailing it down.

MIke

Yep,

Ditto here!

I also think you need to tailor the Grow Media depending on where you live. In Arizona without the rains of Alabama, I would recommend a higher proportion of peat to hold more moisture.

Raybo

Ditto Al, Josh & the other experienced folks above who have helped me with my 19 gal SWC mixes last year that produced abundant tomatoes yet somewhat meely in texture, possibly due to the necessarily high % of peat required to wick water up from the reservoir up thru a 19 gal SWC (Pro Mix). You're probably all set to go with self watering rather than top watering for your 19 gal containers, but I am thinking of converting my large SWCs to top watering this season, so that I can go with a grittier mix and achieve better tasting results. So bottom line is I am not convinced self watering is way to go for large containers, water budget is about the same (evaporation from above ground heat is the same either way you water) and ease of delivering water & nutrients is also a wash (no pun intended). Some have said you avoid meely tomatoes by watering less, but to achieve wicking one must fill the reservoir and it is dry the next day at temps in zone 9-10, so I believe meely taste is related to the mix which is necessitated by SWC. I guess I am posing a question more than adding to your answer.

robertbay,

Have you considered using Landscape Fabric to prevent the roots from going down inside the SWC water reservoir? I had roots in my EarthTainer SWCs going down in there, and this is what it looked like:

{{gwi:19500}}

Since I have lined the Aeration Bench with Landscape Fabric (2 layers, in fact), I believe (although I can't scientifically quantify) that my tomatoes now taste better than the ones when the roots went deep into the water. It just kind of makes intuitive sense, doesn't it?

Raybo

Ditto Al, Josh & the other experienced folks above who have helped me with my 19 gal SWC mixes last year that produced abundant tomatoes yet somewhat meely in texture, possibly due to the necessarily high % of peat required to wick water up from the reservoir up thru a 19 gal SWC (Pro Mix). You're probably all set to go with self watering rather than top watering for your 19 gal containers, but I am thinking of converting my large SWCs to top watering this season, so that I can go with a grittier mix and achieve better tasting results. So bottom line is I am not convinced self watering is way to go for large containers, water budget is about the same (evaporation from above ground heat is the same either way you water) and ease of delivering water & nutrients is also a wash (no pun intended). Some have said you avoid meely tomatoes by watering less, but to achieve wicking one must fill the reservoir and it is dry the next day at temps in zone 9-10, so I believe meely taste is related to the mix which is necessitated by SWC. I guess I am posing a question more than adding to your answer.

Thanks for the help. I have several vaguely connected additional questions. Being new to this discourse I'm not sure whether it would be more appropriate to start a new link ..... but I will try it here. I have quite a bit of potting soil on hand, from my unenlightened past. If I mix it one on one with potting mix, can that be used for the potting mix component? I also have quite a bit of very fine vermiculite ..... could I substitute it for peat? Lastly, I have read in other post's that nutritionally, worm castings aren't very significant. I have about 3/4 of a ton on hand. Any suggestions how I might meaningfully use them?

I'm not sure how you're delineating between potting soil and potting mix, but I can say that mixing two media together that are comprised of all fine particulates, and then adding in the additional water retention afforded by the vermiculite, you're apt to end up with a soggy container bottom. You'd probably be better served if you were to start with a large fraction of pine bark fines & a part or two of perlite, then add enough of your other two media until you get the water retention you desire.

I would use the worm castings in the garden or beds - or on the lawn. I just don't think what little they add nutritionally can make up for the negative impact on structure (reduces air porosity), unless your soil is at a point where it is so open it actually needs additional water retention.

Al