Diatomaceous Earth as a seed starting medium

[Redbaron]

Originally Posted by Baizanator

I used it against two mediums other than Jiffy.

LOL I was just going to mention that Baiz! But the pic you posted was removed.

The only thing I want personally to see in comparison is against vermiculite. I have been using vermiculite for years and years. I haven't found a better or cheaper starting medium yet. DE is pretty cheap though and all you guys had pretty good results. So I may do some experimenting myself.

Did you use a plastic cover? I typically need to use a plastic cover with vermiculite.

[b54red]

Originally Posted by Hotwired

I would be curious to compare DE against something other than Jiffy Mix. My experience has been that pretty much everything performs better than Jiffy.

I have used a half dozen seed starting mixes with the same damping off problems. I am hoping that the UltrSorb will help with that. The UltrSorb has been far superior to all other seed starting mixes I have tried in germination percentages. The truest test has been with two seeds that have always been a pain to get good germination from and that is spinach and cilantro. I am hoping to get the same good results with some of the really slow germinating pepper seeds.

[greentiger87]

Originally Posted by ChrisK

Look great! I have not seen it locally in that coarse grade. The spill absorber and cat litter products are significantly finer.

Optisorb looks very similar to Levant's DE. Autozone doesn't carry it, they only have Ultrasorb and some other Moltan products made from calcined clay.

O'Reilly Auto Parts had Optisorb, but not Ultrasorb. It's like a treasure hunt

[ChrisK]

His stuff looks more like the "diatomite" sold on orchid sites. It looks pea-gravel size to me. The two sizes I have (spill absorbers) seem to work fine for tomato seedlings though.

I've also used 100% vermiculite with good results but don't like that it is so light and it dries too quickly for me. Best results I have are with one of the old school Cornell peat-lite mixes I learned to use when I was a horticulture undergrad at Cal Poly. I think it's something like 70% peat and 30% perlite (v:v) plus some lime. Easy to make in small batches.

Originally Posted by greentiger87

Optisorb looks very similar to Levant's DE. Autozone doesn't carry it, they only have Ultrasorb and some other Moltan products made from calcined clay.

O'Reilly Auto Parts had Optisorb, but not Ultrasorb. It's like a treasure hunt

[greentiger87]

I've never tried vermiculite for seed starting, and I don't use it at all anymore. It always seemed to disintegrate so fast and hold so much water. Counter productive as an additive in many situations.

The thing I like best about DE is that it never, ever gets hydrophobic. The worst thing about peat or coir based starting mixes is trying to get them wet - you're never quite sure if you've done it, it gets so messy, the volume changes constantly. DE accepts water instantly and doesn't compress at all.

[Levent]

My Red Robin in diatomite set fruit under lights.

[Redbaron]

Originally Posted by greentiger87

I've never tried vermiculite for seed starting, and I don't use it at all anymore. It always seemed to disintegrate so fast and hold so much water.

That's why I use it for starts to the second true leaves and when I repot I use a good potting mix. The seeds start in a sterile light mix that holds water, then go to a potting soil or soiless mix.

It is actually the traditional commercial seed starter. I learned it at a commercial seed company I worked for in my youth. Because it holds water so well you can start the seeds in very small cubes, then repot into 3 or 4 inch pots. Or in real large scale commercial they replant into large trays and once they reach the proper size, sell them bare root.

All I did is modify it slightly for myself, taking the best of both worlds. I start in vermiculite, but use a better (and far more expensive) mix for my pots. And I don't use the bare root method.

Then like you said vermiculite does deteriorate quickly, which is fantastic in the garden. As it deteriorates it has a great trace mineral profile.

I am not saying it is the best method, but it works and it is cheap. That's why I would like to see it compared to DE. Maybe I'll do a germination test between the two myself one day.

[Levent]

Capsicum annuum 'Nosegay' in subirrigation pot containing diatomite flowered under lights.

[Levent]

Just a short update, C. annuum 'Nosegay' set fruit under lights.Others to come soon!

[Calcat36]

Wow. This was/is an excellent thread. I'll be starting some hot pepper seeds next month and I will try using this DE medium! Thanks for the info!

[Levent]

Baby tomatoes on Red Robin.
Diatomite is not only a seed starting medium but also a high yielding growing medium for almost all plants including tomatoes.My deep freezer is full of chilli pods from plants grown in straight diatomite last season, more than I could consume actually! I hope some members dare to grow plants in diatomite instead of transferring them to soil.

[ChrisK]

I'd be interested in your system. My tomatoes are looking pretty sad in the ultrasorb.

Originally Posted by Levent

Baby tomatoes on Red Robin.
Diatomite is not only a seed starting medium but also a high yielding growing medium for almost all plants including tomatoes.My deep freezer is full of chilli pods from plants grown in straight diatomite last season, more than I could consume actually! I hope some members dare to grow plants in diatomite instead of transferring them to soil.

[RayR]

Originally Posted by ChrisK

I'd be interested in your system. My tomatoes are looking pretty sad in the ultrasorb.

They shouldn't be. How far along are they and have you fed them anything?

[ChrisK]

Second set of true leaves just starting to come out. Yes, they've been fertilized. I may fertilize a little heavier and see if they green up.

Originally Posted by RayR

They shouldn't be. How far along are they and have you fed them anything?

[RayR]

Originally Posted by Levent

Baby tomatoes on Red Robin.
Diatomite is not only a seed starting medium but also a high yielding growing medium for almost all plants including tomatoes.My deep freezer is full of chilli pods from plants grown in straight diatomite last season, more than I could consume actually! I hope some members dare to grow plants in diatomite instead of transferring them to soil.

I'm up for that challenge Levent. I'm going to try growing a few hot peppers in Diatomite to maturity in a few containers. It will make an interesting side project to my DE seed starting experiments.
I'll be using organic methods like I did last year for seed starting in DE, buy I'll take it to another level from what I've learned over the year.
For organics to work in a system with an inert media you need suitable microorganisms to quickly mineralize a soluble organic nutrient since you don't have the complex mix of organic material and biota as you would in soil. General Hydroponics has been working in the area of perfecting Bioponics (not the fish culture version) for some years now and they say Trichoderma fungi are the organisms of choice for this task. They are highly adaptable, and grow fast as long as they have a stable environment with warmth, oxygen, consistent moisture and a food source.
My concern was would Trichoderma be happy in Diatomite, but I read a study a while back done in India where they successfully cultured Trichoderma harzianum in Diatomite with only molasses as a food source as an inoculant to be spread in an agricultural field.