Diatomaceous Earth as a seed starting medium

[RayR]

Originally Posted by Airangel56

My experience with seed starting in DE was not what I would call a success. What did germinate heaved out of the DE before establishing any viable roots. I rescued some and potted them up in a mixture of organic potting soil and DE. The portions were 1 part DE to 2 parts potting mix. This did produce some very healthy seedlings. I am wondering if I didn't plant the seeds deep
enough initially.

That's probably the case, I found that planting Tomato, Pepper and Eggplant seed down about 1/4" or a little less works the best for me. Of course you do get those occasional defective seedlings that don't produce a tap root. I see that mostly with peppers. I just toss them.

Originally Posted by beeman

Same here, disappointed, but I believe my problems was from a different direction.
I tried using a different DE, Qualisorb bought in Canada, supposed to be the same as used in the US.
The difference, I used a 3 inch pot, and don't believe the water wicked up fully, as the Tomato seed all suffered with 'Helmet head'. Very few germinated and were weak, repotted into soil, now doing fine.
So I Tried again, this time using a pot only 2 inches tall, covered with 'cling film'. Little to no germination, even though on a heat pad, other seed in addition to tomato, included peppers, lettuce, beets.
It seems to me that bottom watering in the initial stages leaves a lot to be desired, it was only after 'spritzing' daily that i got any results.
I will try again, when I get my garden on the go.

Qaulisorb #628N is what you used?
It looks similar to the DE absorbant that NAPA sells under their brand. It's also made by EP Minerals, medium sized granules like Moltan Optisorb. PH is supposed to be 7.0, which is fine.
That's really strange that it would not have wicked up fully as long as you added enough water, you can tell just by the darker color of the DE when it is wet.
The only seeds that I've had trouble getting good germination this year is certain varieties of peppers, most were 3 & 4 year old seed. Helmet heads are more common with peppers, I got only a few with tomatoes. I've never seen a epidemic of tomato helmet heads like you got.