Diatomaceous Earth as a seed starting medium

[meadowyck]

Rockporter, I just checked and we have an autozone in my town, so I'll check them out this week to see, thanks for the suggested places.

[tuk50]

Ray, your right about ultrasorb.. I posted the wrong moltran product. http://www.oreillyauto.com/site/c/se...word=ultrasorb
this is what I used. (corrected site)

[RayR]

Originally Posted by meadowyck

Well it is either the type of DE that I have (food graden so it is very fine) or the weather we are having, or maybe both, but my seed starting is terrible.

I'm going to go back to my seed soil and heat mats in order to get the seeds to sprout and stay living.

This is the first time for me to have seeds come up with the seed cap still on them, another member here pointed me to a thread and they are called helmet heads, well that is crazy as 95% of those that have this usually end up dying off.

It looks like cement, it's crusting at the surface, air can't penetrate to the roots. Not good.

[Rockporter]

Originally Posted by meadowyck

Rockporter, I just checked and we have an autozone in my town, so I'll check them out this week to see, thanks for the suggested places.

OK, make sure it's the Ultrasorb 100% DE and not the one I originally got that was actually clay. I had to take it back lol. Good luck with your new experiment.

[RayR]

Originally Posted by tuk50

http://www.amazon.com/OIL-DRY-ABSORB...words=oil+sorb
I ordered this from amazon and it worked well for all my peppers, tomatoes, eggplants and so far this fall brussel sprouts, cabbage, kale collards and kohlrabi are doing great in it now.

Are you sure you are using SAFE-T-SORB? That not DE, it's Montmorillonite clay.

[tuk50]

Ray, I got it in early spring when I first noticed this thread... unless it has changed I think it is de.. nice size white pellets a bit smaller than bb's and has worked well. I couldn't find it here locally and ordered from amazon. I don't have the bag after dumping it into a bin in the greenhouse. I'll try to find my invoice and check back.

[greentiger87]

This is calcined DE we're talking about right? If you put it in a cup of water, the large particles wouldn't dissolve?

Don't mean to be a chicken little.. but inhaling calcined diatomaceous earth dust is pretty bad...calcining converts the silica to the dangerous crystalline form. Calcined clay dust and granite dust are hazardous too, but not to the extent of calcined DE. Natural granite has a low crystalline silica content, and I believe Turface is up to 5% crystalline silica.

The effects aren't acute or obvious - it's chronic, long term, cumulative damage to the lungs. You may not feel consequences until you're much older, but the damage is happening whether you laugh it off or not :/ Think about the people that love you and just endure the annoyance of wearing a cheap respirator (not just a dust mask!) if you're going to use it.

[RayR]

Originally Posted by greentiger87

This is calcined DE we're talking about right? If you put it in a cup of water, the large particles wouldn't dissolve?

Don't mean to be a chicken little.. but inhaling calcined diatomaceous earth dust is pretty bad...calcining converts the silica to the dangerous crystalline form. Calcined clay dust and granite dust are hazardous too, but not to the extent of calcined DE. Natural granite has a low crystalline silica content, and I believe Turface is up to 5% crystalline silica.

The effects aren't acute or obvious - it's chronic, long term, cumulative damage to the lungs. You may not feel consequences until you're much older, but the damage is happening whether you laugh it off or not :/ Think about the people that love you and just endure the annoyance of wearing a cheap respirator (not just a dust mask!) if you're going to use it.

Not flux calcined, it's amorphous fresh water DE, under 2% crystalline silica

[b54red]

Uh Oh. I think I have messed up somehow. My spinach seedlings look sick and I don't think it is damping off. I may have over watered or over fertilized them. I got a bit paranoid about them drying out so much and wilting over so I kept them watered every day and I fear I may have overdone it. None of the other plants are having a problem as a matter of fact the lettuce seem to like the added moisture. I guess I will just have to keep a close eye on everything and see if anything else has a problem.

[greentiger87]

Originally Posted by RayR

Not flux calcined, it's amorphous fresh water DE, under 2% crystalline silica

::Claps hands:: Awesome! I just picked some Ultrasorb up from Autozone on the way home from the dog park. Excited to try it. Does it deteriorate with use?

Anything that means i don't have to work with super hydrophobic peat or coco coir is something I can get behind!

A quick google shows that the cannabis community uses it successfully for cloning/rooting cuttings.

[Diriel]

It is very durable, you would need to abuse it pretty hard to have to replace it anytime soon. That is one of the reasons I decided to run with it.

Gary

[b54red]

I have already bought my second bag so I guess I am liking the results. I am sure I will find some drawbacks versus regular seed starting mediums but so far it is proving easier to work with in most ways. It is not as easy to top water unless you use a very gentle shower; but bottom watering is so much easier and quicker. I do know it is a good bit more likely to fall away from the roots when transplanting especially if you try to transplant when the DE is a bit too dry. I haven't tried it as a replacement for potting soil when potting up to larger cups but I may try it to see how it works. I think it would be a bit more expensive and the larger cup might present more problems when transplanting. Peat will hold together better when removing from a cup than the DE especially if a good root ball has not formed yet. One other plus to the DE I have noticed is that the DE is far more forgiving if you accidentally cover your seed too deep when planting.

[RayR]

Lettuce does pretty well in DE, these are 14 days from seeding in a 4" pot.
The other day I noticed the roots coming out of the drain holes, so it was time to transplant them in soil in containers. It was fairly easy to separate the seedlings without too much tearing of the fine roots.

[Rockporter]

Boy am I doing it all wrong, one seed per hole lol. I thought if I did it that way and I didn't get to transplant soon enough then the seedlings would have some room for their roots. I will have to try it your way.

[Baizanator]

Originally Posted by RayR

This experiment started in January when I was wondering how Diatomaceous Earth would work as a seed starting medium. I know that DE is used by some folks in hydroponics as a growing medium, it is also used by some folks in Bonsai, and studies have been done using DE as a soil amendment, but I’ve never ran across anyone who has used it as a seed starting medium. So my curiosity forced me to try it. I had some Blue Ribbon D.E. Premium Cat Litter manufactured by the Moltan Company which I have used as a potting soil amendment, so I had something to start with. From my research on DE I found that the PH of DE can vary depending on where it is mined, so I did a PH test with my digital PH meter and the Moltan product came in at a PH of 6.8 which was perfect, the same as a standard peat based seed starting mix. My first experiment was with Llia Onion seed and the results were very impressive, I grew some very healthy onion seedlings with no problem.
My second experiment came in mid-March with tomato seeds. I found that Moltan makes the same DE product sold as an oil absorbent called UltraSorb which I found right down the street at the local AutoZone in a 15lb bag for $5.99. The only difference between UltraSorb and the kitty litter was the granule size, the UltraSorb is a much less coarse granulation (more like coarse sand), which was easier to work with.

I seeded 24 Brandywine and 24 Black Krim, half in Jiffy Seed Starting Mix and half in DE.They were bottom watered with distilled water, put on the heat mat under lights and given no nutrients until they developed their first true leaves. The germination rate was exactly the same. Here is what they looked like today. See any difference?

Ray, your research has inspired me. I'm working on a project for a class and it is to be some sort of "mini-study" that can be completed in one semester. We're testing the viability of Diatomaceous earth as a seed-starting medium versus a commercial peat-based mix and a coco noir mix.

We've planted ten individuals of five different cultivars (30 of each/50 in each medium.) We're going to calculate germination rates and seedling weights at an undetermined stage. Below are the flats that I planted today.