Bark and sand with slow release fertilizer.

fine bark(30%), perlite(20%), Sunshine growers mix #2(20-30%), sand (10%) peat (10%). The Sunshine gowers mix has all of the wicking agents you need. No need for coir if you use this. It has no food, so you will need to add some food, but I have best results with my mixes when they are lean.
I also add dolomite, as it feeds just about all conifers.
Steven

Thanks!

Went out to the growing shed (that is shared with my daughter's 35 or so canaries) to assess how the roots of transplants from the cloner were doing in different mixes that had been used. It seems those moved from the cloner into a 50/50 peat perlite (a rooting mix) were doing the best. Still having trouble with survival when transferring the rooted cuttings from hydroponic to a potting media. I need to start considering pH as a factor too...

Steven and Ron, I'll mix some sample batches of your mixes when planting into 4 inch and larger pots. The SunGro catalog shows the #2 mix to be peat, perlite, gypsum, lime and wetting agent. How much dolomite lime and gypsum should be added to a cu ft of the final mix if I don't use Sunshine #2? Do you use this potting mix recipe for all your plants Steven, or just the conifers?

Thanks again,
Barbara

When I worked on an azalea farm we potted into pure bark. The owner would go around at night and water with an injector, so they got a frequent liquid feed.

Even with fine bark and sand the bark rots and becomes too moist rather soon - I certainly wouldn't deliberately add things like peat etc. If you are in a hot climate decomposition of the organic component of the mix could be even more of a problem than here.

Now I'm getting confused Ron! There are just too many options and variables.

What would you suggest to replace the bark and peat in potting mixes?
Coir is supposed to break down slower that peat. But is there a reason why Sunshine's coir mix still has peat listed as it's major ingredient, rather than simply being coir and perlite...price?

So many questions....

Barbara

Peat is actually hydrophopic, while coir is a wetting agent, or "water wicker', pulls water instead of pushes (like peat). We use Peat to add acid and to add orgainc matter that does breakdown quickly.
Dolomite has been like a magic bullet (for us) in providing food for the plants. A very old hand at conifer growing taught me this trick a few years ago and it has made a huge difference including survivability of transplants.
I use 4 cups dolomite to 4 cubic feet of mix.
By the way, I am by means saying this is the "best" mixture or that any one elses is not good. This is simply what we have found works in our Nursery. I do know from talking to the folks at Iseli that the biggest issue they have had is thier water. Ours is comes from a very deep well (242 feet into granite) and is full of trace minerals.
Iseli had a HUGE problem with water being too rich in iron and lost a bunch of fresh transplants. I do know that if you are using a highly clorinated water source, it is best to let the water sit, open, before using it on your cuttings.
Steven
Steven