Specialty Gardening: Container Soils - Water Movement and Retention III , 1 by tapla

tapla wrote:
Peat is light to ship, plentiful, inexpensive enough to present a greater potential for profit for potting media (soil) packagers, and many/most people are willing to pay for the convenience of not having to go to the effort of making their own soil. As you probably already know, I have found that with only a little sweat equity, you can make a much superior soil for less.

I think that to make a judgement about whether orchid soil is better or best, we would need to know a little about it's composition, primarily the size of the particles and their physical characteristics. I think it's important to understand that what this thread emphasizes isn't so much the particular soil recipes; rather, I wanted to point to the fact that well-aerated and free-draining soils that have, inherent, the ability to retain those properties for the intended life of the planting, offer much greater opportunity for plants to grow to their genetic potential within the limiting effects of other cultural factors. The soil recipes are just good examples of how you can implement that concept.

For several reasons, soils that support little or no perched water, yet still offer good water retention, will be more productive AND easier to grow in, offering a much wider margin for grower error in both the watering and fertilizing depts.

I use the 5:1:1 soil, pine bark:peat:perlite for all my veggies, mixed floral display containers, and the short tern plantings (1-2 years in the same container). For ALL my trees/shrubs, houseplants (including cacti and succulents) - all the long term plantings I think will be in the same soil for 2 years +, I use the very stable 'gritty mix' seen in the picture.

Al