Hi
I don't usually venture over to this forum but was hopping to find an ATP person that has knowledge about J. Maples. My plan is to plant a J. Maple in a very large pot but my question is what will I mix together for soil? Garden compost, bark, gravel? This tree will be living in here for years and would like to put what is best for it in the pot.

I live in western Washington, the state, and need the items to be available here. I'm worried about the soil getting to compacted over the years for the root. Any ideas?

If you ask 100 guys who grow bonsai what kind of dirt to use, you can reasonably expect to get 110 answers.

Acer palmatum grows pretty strongly in pots. I would expect you are going to need to remove a portion of the soil every other year.

All trees do better with very fast draining soil with about half being coarse stone. I use layer or turkey granite grit from the farm feed store. Its affordable and mostly does not need to be sifted.

A tree will grow in soil with a fine particle size, in your yard. In a pot it needs more access to air. Forget that and you will ever be battling (and loosing at) root rot.

I get less critter damage in the winter with osmocoat pellets than organic fertilizers. Four legged critters go where their nose takes them.

If memory serves a more acidic mix is better? i.e. don't use limestone. I've been adding pine bark mulch straight out of the bag to improve aeration. Make sense Tom? Good luck on you're project spring!

Thanks, We have acidic soil here so that's good. I didn't think of using grit in this application. I use that for my sempervivum all the time.

I agree 100% with Coopice - the key is well drained soil. Avoid fine particles like sand, compost, dirt, etc, that will compress when wet.

Al Tapla's 5-1-1 Mix

5 parts pine bark fines
1 part sphagnum peat
1-2 parts perlite
garden lime
controlled release fertilizer (not really necessary)
a micro-nutrient source (seaweed emulsion, Earthjuice, Micro-max, STEM, etc,)

Or you can use Al's Gritty mix are a 1:1:1 ratio of:
1 part Bark Fines
1 part Turface ( Profile) like on the LL baseball fields
1 part Granite ( chicken grit)

You may also need a bag of "Gypsum - Calcium Sulfate" IF you are NOT using Foliage Pro 9:3:6 ( fertilizer) . If you have chosen to use Foliage Pro as your fertilizer you will not need the calcium. (The Foliage Pro is HIGHLY recommended by several experienced growers on these forums! I had to buy mine on line, it is not available in stores in my area.)

I haven't ventured into this forum much, but thought any Japanese Maple fans might like to check out this post under Garden Photos:

The thread "Amazing Maples" in Japanese Maples forum