Diatomaceous Earth Organic Seed Starting Mix Experiments

[RayR]

I'm kickin oiff this thread for those who like to experiment with new ideas for growing mediums. Last season I continued working with granular Diatomaceous Earth by mixing it with coir and even worm castings to maybe capture the best of both inorganic and organic worlds and see what happens. Well the results were very encouraging with tomato seedlings so I just had to do again and even try some other inputs like some rich commercial bagged composts. More on that later when I get to tomatoes, peppers and eggplant.

First up is lettuce. For that I started with a straight 50/50 mix of granular DE and General Hydroponics Coco Coir back in the second week of March. Doped the medium in 1.5" cells with some organic nutrients and some microherd inoculant (Some Great White and some AZOS that I had left over from last season) and got those lettuce seeds off to a start. The plan was to grow the transplants indoors under T8 lights until I could get them transplanted in containers outside sometime in late April so I could harvest some really big heads of juicy lettuce in early to mid May. Could have got them big and an earlier harvest, but I knew with the very cold spring we had it wasn't going to happen. Lettuce like cool temps, but not that cold.
They grew pretty well indoors in those little cells so I potted some up in 4" pots and continued growing them under the lights until the temperatures outside were warm enough and the container soil unfrozen.

The first picture is the 5 Rouge Grenobloise plants that I grew in those 4" pots on the day that I transplanted them outside on April 19th.

The second picture is one removed from the pot so you can see the root ball. The coir and DE are a great combination. It stays nice and loose allowing for oxygen to get to the roots. And for bottom watering it wicks just as well as DE alone.

The third picture is a close-up of a section of those fuzzy roots and the mix.