Diatomaceous Earth as a seed starting medium

[RayR]

Originally Posted by Calcat36

Hello RayR! I was finally able to locate a bag (.33lbs/14,97kg) feels like 50 lbs to me of Moltan Oil Absorbent for $7. Way more than I need, but if it works I will put it all to good use. It doesn't specifically list what it is other than #7133 and "natural earth product."

Am I on the right trail? Thanks!

That's the wrong one, it's not DE. Oil Absorbent is their Montmorillonite clay, which I already tried is too acidic for seed starting. If you got that #7133 at Autozone, they also carry Ultrasorb which is part# 8818, 100% Diatomaceous Earth, 15lb bag, that's the one you want.

[Calcat36]

I just re-read the post and read the FINE PRINT on the bag. That is the only oil absorbent material this auto zone carries. The employees there were not very helpful either, with respect to, "where is the oil absorbent stuff?"

Tractor Supply Company tomorrow. If they don't have it, I don't need it!

Thanks for the help!

[RayR]

Originally Posted by Calcat36

I just re-read the post and read the FINE PRINT on the bag. That is the only oil absorbent material this auto zone carries. The employees there were not very helpful either, with respect to, "where is the oil absorbent stuff?"

Tractor Supply Company tomorrow. If they don't have it, I don't need it!

Thanks for the help!

They don't carry it??? It's right on their web site! See here

If they don't have it in stock, they can order it for you and have it at the store in a few days on the truck with their normal parts shipment.

[Calcat36]

Thanks again RayR! I did check the website, it said they had it in stock until I entered my zip code. I tried to call the store but they were closed.

Funny thing is, I worked there when I was 17 years old! I know a manager at another store that I will call tomorrow. I can't wait to see the look on her face when I tell her what it is for!

I was really impressed with the root pictures posted. That is much better than anything I have ever had, outside of putting a cutting in water, specifically Chinese 5 Color. They developed strong roots and when I put them in soil, they died.

If anything, the best thing this medium will give me is a positive attitude and confidence to keep trying!

Thanks again!

[Rockporter]

Originally Posted by Calcat36

Funny thing is, I worked there when I was 17 years old! I know a manager at another store that I will call tomorrow. I can't wait to see the look on her face when I tell her what it is for!

He he, I got the question if I wasn't sure I was growing marijane indoors instead of starting seeds at my local store and had explained what I needed it for. Ha ha, I should take the manager a tomato seedling to grow out.

[Calcat36]

Funny Rockporter! If I get that question, I'll ask her if she has any seed!

[Rockporter]

Originally Posted by Calcat36

Funny Rockporter! If I get that question, I'll ask her if she has any seed!

[b54red]

Originally Posted by nativeplanter

Bill, do you provide any heating for your seeds? My seedlings grow in a south-facing porch surrounded in storm windows (screens if it is warm enough). I've found that germination can be spotty if I start right in the pots, due to the cool night temperatures. I seem to get better results if I pre-sprout in a dish over the warm cable box. Heating mats would be optimal, but boy, they are pricey.

I do not use any heating so sometimes my seeds are slow to germinate; but most of them eventually pop up especially since using the UltraSorb. I start most in a small attached greenhouse that heats up nicely in the daytime and if the nights don't get too cold they are okay in it. I also use my screened in porch with plastic sheeting stapled over the screening to keep it warmer. The porch is much larger than the greenhouse so it holds the daytime heat a bit longer and I can set a propane heater in it if the night temps are going to stay in the low 20's. I did lose some tomato seedlings a few years ago in my greenhouse when the temps dipped into the teens for a few hours. The biggest problems I have had in the past is when we get a week or two with very cloudy or rainy weather. I then have problems with leggy plants or damping off. I'm hoping the UltraSorb will eliminate most of the damping off problems that I had with the more traditional seed starting mixes.

I have a question--I have some Ultrasorb that I used to root some Swedish Ivy cuttings(it didn't work-the cuttings got rotten in mail transit) Would it be OK to soak the DE in some bleach water then strain it to use? There's quite a lot of it and I hate to waste-

[RayR]

Originally Posted by JoParrott

I have a question--I have some Ultrasorb that I used to root some Swedish Ivy cuttings(it didn't work-the cuttings got rotten in mail transit) Would it be OK to soak the DE in some bleach water then strain it to use? There's quite a lot of it and I hate to waste-

I don't think I would use bleach (Sodium hypochlorite [NaClO]). I think since DE is very absorbent it would be difficult to purge the bleach entirely by rinsing, second NaClO breaks down in water and releases Sodium cations which would easily get bound to the DE's cation exchange sites. Who knows what other reactions could occur from bleach in DE that could be detrimental to plants?

Hydrogen Peroxide would be much safer.

[Levent]

No need to apply chemicals.Heating used diatomite in oven (200C around half an hour) carbonises organic decayed residues,desiccates and sterilises the medium.It's better to wash diatomite later to get rid of remnants.Diatomite is a fairly inert and stable mineral rock therefore its physical properties or chemical composition don't change after heating process.Hope it helped.

OK- thanks for the input- I will just microwave it!

[fortyonenorth]

Originally Posted by RayR

That's the wrong one, it's not DE. Oil Absorbent is their Montmorillonite clay, which I already tried is too acidic for seed starting. If you got that #7133 at Autozone, they also carry

pH should be a major concern for seed starting--at least there's a much greater range of "acceptable" than there is for in-ground growing. Most of the adverse affects of low pH are based on making some trace elements overly available to the point of becoming toxic. These aren't generally a factor in container mediums.

Thanks for posting the results of your experiments, Ray. It doesn't surprise me that you've had good success. IMO, most commercial potting mixes are much to moisture-retentive. That inhibits root growth. As you've seen, the well-drained medium fosters exceptional root growth.

I've been doing some seed starting and vegetive propagation using calcined clay, granite fines and a small amount of a bark/peat mix and it behaves exceptionally. There's virtually no way to overwater and things are really flourishing.

[Levent]

C. annuum 'Nosegay' This one is the smallest chilli sort.
I would say that I succeeded to grow it in diatomite under lights.However it was not a hard work!
I took the photo today.

I have one more question for someone who has had experience with DE... When I get ready to sow seeds in my 5oz plastic cups, should I moisten the DE before filling the cups or after the seeds are in?