Not sure that I would use bark mix in containers (and I would assume that you'd have to water more frequently). For my money, I find that bark is great for use in the garden as it does lighten up the soil, but it needs some time to break down to provide nutrients.

I LOVE "Pro Mix for Vegetables" which is organic and available in Canada. I don't know if they have quite the same thing in the US, but regular Pro Mix doesn't have any nutrients and doesn't work very well for me, even when I remember to fertilize my plants!

Linda

Check out the 5-1-1 mix that is highly recommended over on the Container Gardening forum here.

Otherwise like Linda I prefer ProMix BX above all others. I have no issues with bark in my mixes but not 60% bark, more like 20%. But it also depends on the type of bark and the size of the chips. But yes, with any highly draining mix you will have to water more often. Especially in such small containers.

Dave

I tried using the 511 mix, but never kept up with fertilizing , so I didn't get good results, next time I would add some CRF like osmocote or something. The mix did drain really well, but I didn't have any problems with it drying out to fast as long as you mulch it some. Another plus was how light the mix is compared to my other container mixes, made it easy to move my 15gal containers.

jm...to keep it simple...I just add 1/3 cactus mix to a quality potting mix. This increases the "drainability" of the mix. It has worked out great for me. Lots of people have their favorite "custom" mixes.

I have made and used some version of 511 (4-2-1) with good results. The problem with 511 is that the main component ( pine bark , 70% of the mix ) is not an standard item and can vary in size and quality. And it might not be even available in most locations.

In the absence of 511 option, ProMix , Sunshine are better ones. Most , if not all, potting mixes are peat moss based with about 20% perlite.

I would avoid MG Moisture Control stuff.JMO

Sey