It may be something as simple as your watering practice isn't appropriate for both mixes equally (cells in same tray). Your peat perlite could drain more slowly, be harder to remoisten if drying. The peat perlite will also be more acid PH, although I don't know if that is your difference. It's also nutritionally inert, which shouldn't matter remarkably with germinating seeds and seedlings, they come equipped with their own nutrition needed for germination and first growth.

The Agro in comparison is sphagnum peat moss, humus, coconut husk fibre, perlite, lime, natural fertilizer, OMRI gypsum. In the case of your trial, it doesn't look like 'less is more' although I typically find that to be true. Coconut fiber has never been one of my most fav ingredients for container mixes, it seems to be working for you. This time ;0)

Thanks for your feedback. I did notice my mix did dry out faster. Think the stunted stuff and slower germination can mostly be attributed to uneven moisture?

Agro Mix contents:

• Coconut Husk Fiber highly effective for long term moisture
• High quality screened peat moss
• Perlite and vermiculite
• Nutrient charge, lime and wetting agent
• Ph range 5.5 - 6.5

It was my experience as a student long ago that mixtures made from and peat like substitutes all benefited from a wetting agent. And dish soap is inexpensive, safe enough that you use it for your food handling items and only a drop will produce surprising results.

So you think it's moisture related too?

It is really an apples vs. oranges comparison to a large degree - different components, different particle size, different pH, different moisture levels both initially and throughout the growing process.

Dave