I can't tell you a specific brand, as packaged soil mixes vary widely by locale. Chances are you will find better quality mixes at a nursery or garden center rather than at a box store.

What you want to look for is a bark-based (not a peat-based) mix and they are harder to find as a bagged or prepackaged product. I would not pick the Promix HP as my first choice as it is 75% peat (and never add compost to a container soil!!). If you can find it, the Promix BRK is bark based, so a much better choice right out of the gate.

Another good choice is Fafard's 3B Metro Mix. Both of these are closer to the 5-1-1 than just about anything else you can find bagged.

You'd be better off using plain old pine bark mulch, or better yet, "Soil Conditioner" rather than PB Nuggets. Nuggets are too big.

What products are available in your area?

I've never seen soil conditioner in my area. I will look around at pine bark mulch. The one type that comes to mind had a lot of stringy bits and sap wood in it. Still might be less work than dealing with nuggets

Not very helpful... but I don't think you will find good bark here around the GTA. I've spent months looking for it without success. We have nothing like the bark selection of the USA.

Gro-Bark Milton is probably your best bet - if you call they can answer your questions as not everything is necessarily on their website.

You may also try Plant Products Inc in Ancaster. They have huge packages of Promix and other things for commercial operations.

gardengal48 (PNW Z8/9) you wrote (and never add compost to a container soil) Sorry I don't understand this. Would you explain? thank you

You do not want concentrations of organic matter in a container soil. The best container soils are those that offer both durability (not inclined to breakdown or decompose) and a high textural component. That eliminates things like compost, manures or worm castings. All will continue to degrade and breakdown and as they do, the individual particles get smaller and smaller, obstructing fast drainage.

Fast drainage and aeration are the key elements in a container soil. That's why the best container soils are soil-less mixes that contain a high percentage of grit/perlite/Turface (a calcined clay) and composted softwood (conifer) bark and minimal amounts of peat. No garden soil or topsoil, no vermiculite, no compost or manures.

This link to a very long running thread (10 years +!!) on the Container Gardening forum may help to explain it all in greater detail - Container Soils and Water Movement.

"Best" requires consideration of a lot of factors, such as how often you want to water, can you drain the runoff, dealing with fertilization, how often do you expect to repot, what will you plant in it with and on and on. Organic gardening suppliers, shops that deal with hydroponics might be good places to go and ask questions as well as provide "pro" bagged mixes or inorganic elements if you decide to do that. There's always mail order if you know what you want.

thanks,gardengal48 (PNW Z8/9)

You are most welcome :-)) That's my best buddy Chewy. He's a great gardener!!