Go for it. I sort of tried to make one of Al's Mixes before and got hung up on the micronutrients. There are plenty of people doing container gardening so I think you will find substitutes for what you can't find if you keep reading. Sweet William made the mix with pine bark fines and he used Shrub and Tree soil sold at Lowes in a green bag I think it is Scot's. I have not tried the gritty mix. I think your tree might actually be safer in a tub. The borers are what always got my fruit trees of the peach/plum types. Gail (Ozark N.) gets perlite for me in big bags for about $20. I think the Botany Shop carries it. She doesn't carry it but I ask for it and she has it next time I come. I never found the turface.

In spring of 2011 I mixed up Sweet William's formula and used it for my containers. He recommended something from Espoma that had mycorr---hae??? in it and I found a bag of it at Lowe's. I also used a bit of this scattered around my newly planted tomatoes and other vegs.

It was just like making stew (I love to cook!) and I couldn't tell you the "recipe" but even though I never found Turface either, I did have perlite, pine fines, shredded spaghnum and the nursery mix Helen mentioned. For some reason, I didn't use that last year, used a bagged potting mix, and the results weren't nearly as good.

I'm always experimenting, Christie, and I'd sure be interested in your tree-in-a-pot venture. Do let us know what you decided to pot it in and how it's doing.
Sunny

I had a long post ready and just lost it!!!!

I have a standard apricot tree that is so old that it is beginning to die and have already planted a new one in the orchard.
The old one is either Sungold or Moongold from Miller Brothers in NY. For many years I got very few, if any, but the last three years, I have had enough to make several batches of jam and even freeze a few. Maybe our weather is changing.

If I were going to grow a tree in a tub, I would go to Wickman's and ask them what mix to use and pay them whatever they asked for it. Those folks know what they are doing. All those trees next to Fort St. are in tubs covered with mulch and some have been there for many years.

I have often thought about growing a fig in a tub but all my outbuildings are probably too cold even if I could wheel them in at night.

Good luck; let us know what you do and how it turns out.