The location of the maple is ideal for them.

It sounds like you won't be disturbing the root, then you should be okay to transfer it to a bigger pot at anytime. It seems like every nursery has their own soil preference. In the end, it shold be quick draining. I'm avoiding product like Miracle Gro soil because they added wet agent to keep the moisture better. You shold look into the Al's Mix 5-1-1 recipe as it's quick draining...

Make sure those barrels have holes on the bottom.

PS, wait for others to chime in as I'm still learning :)

Doing some research I have stumbled upon the AL's Gritty Mix, would this be good for the Maple? DO you need to feed the tree as there is little organic material?

Al's Gritty Mix is the ideal mix, but I find myself watering it everyday. And yes, you would need to fertilize them more frequently.

Search for Al's 5-1-1 mix. It holds moisture longer than the gritty mix. Also, some of the ingredient for the Gritty mix is hard to find.

Another option is that I read people suggesting for good drainage.

1. Potting Soil (no miracle grow)...
2. lava rock (small size about 1/4 inch) add 10%
3. pine or orchid bark (small size about 1/4) add 10%

I prefer finding soil that has no "manure" in them.

Again, everyone has their own ingredient.

So some good quality potting mix plus Bark and lava rock is a good option?

You can substitute lava rock with perlite.

Since you're doing a container, it's recommended to repot every 2 years, depending on the root growth. You may need to do some root pruning if you going to keep the same pot.

If you plant it on the ground, then you don't need to worry about the repotting and root pruning.

May888-That is another question I asked whether I should go directly into the large Wine barrels or pot them up to a cheap plastic post that is smaller and would sit inside the wine barrel till a second pot up tot he wine barrel in a year or so?

It's really up to you...

In my opinion, a black plastic pot doesn't look too good for display.

This is what I would probably do since you have the wine barrel already. Keep the plant in that pot and inside the barrel. Get some small mini bark and add it to the gap inside the barrel with them. Cut the top circle of the tree black pot when it touches the dirt inside that pot. And then scatter some of the mini bark around the edge of the black pot to cover it up. And no one will know that you have a pot within a pot :)

Let me show you pic of mine :) I still have the original pot inside the bigger pot.

This post was edited by May888 on Tue, Jun 3, 14 at 13:48

In a half whiskey barrel, repotting may only be required every five years or so. And in NoCal, I'd look for a Kellogg product - Gardner&Bloome Acid Planting Mix or Master Nursery Acid Planting Mix. This is a great, durable, barky potting soil that maples thrive in. I grow all my containerized trees in this mix and that includes over a dozen JM's.

Personally, I would have no issues about planting from nursery pot to container now.