Basic epiphyte mix:

2 parts peat moss
2 parts fine fir bark
2 parts perlite
1 part fine charcoal

ABG basic nursery mix:

1 wheelbarrow composted pine bark
1 cup lime
1 shovel builder's sand
2-4 gal perlite or Permatil
1/4 cup bonemeal

Gesneriad mix:

1 part Pro-mix BX
1 part fine charcoal
3 parts perlite

Begonia mix:

5 parts Pro-mix BX
2 parts perlite

 

What is the lime used for in the basic nursery mix? Is it just to adjust the pH or is there another purpose?

 

Well it seems that the ABG we use is based off the ABG epiphyte mix. Maybe they used tree fern in the past. It appears someone replaced half the peat with milled sphagnum.

The other mixes I find unremarkable and have never heard of anyone using them or referring to them as ABG.

I am most curious about the claim this was developed at ABG. Developed to me sounds like someone tested it. But I was never able to find any papers where some sort of testing was done.

 

No. The ABG we used is exactly their Nepenthes mix with I gave in the OP. And, what are you talking about, "developed"? The only person in this thread that used the word developed is you. That aside, development does not imply testing was done and not being able to find something does not mean it doesn't exist.

 

curious...what "form" of lime is used? And it is probably to temper the pH of the pinebark...where does one find "composted" pine bark??

 

Here's a good place on the Lime question Does Your Lawn or Garden Need Lime? | North Carolina Cooperative Extension

Composted pine bark is simply pine bark from one's compost pile. The recipe, as do all, assumes you have the required components.

Edite: I got the above link from this link: Chalice of Answers but this must come as an addendum to the origional as some have assumed I intended to be rude when using it. This, of course, is false. It's slightly enough amusing to pass as funny.

 

I understood that the ABG that we discuss here is a mix that somebody at Atlanta Botanical Gardens developed specifically for use as a fast-draining terrarium soil.

Regular potted plants would dry out really fast if you put them in ABG mix.

 

Yes it is. More specifically it is the same mix they use for Nepenthes and probably a few other related Genus.