Diatomaceous Earth as a seed starting medium

[ChrisK]

No fertilizer yet. I usually don't fertilize until first true leaves are larger.

Originally Posted by JamesL

Chris,
Do you have any fertilizer in the DE?
I have a similar observation with respect to growth and I made sure to put it in my notes for next year. I didn't really notice a difference with germination, but I do pre-germinate all my seed.
Growth was definitely slower without the "spurts" you typically see. Slower growth was beneficial to me with respect to grafting though, enabled me to get better matches.

PS - I did do a side by side of DE pre-charged with SeaStart 0-4-4 and without. No differential in growth to true leaf stage.

[Labradors2]

My intitial seeding in DE worked really well. In fact I did a test of 2 pots of DE and 3 pots of soil-less mix with some cukes, and the DE ones are strong and healthy with their second leaves, whereas two of the others have deformed cotyledons and don't look as if they will even make it. The third didn't sprout.

However, my peppers and eggplants all came up fine, but now they are really struggling. It's been cold in the house too, but I think it might also be that I'm bad at applying fertilizer.

Can someone tell me how often to apply it, at what strength, and how much?

I have some really old CIL fert, (5-10-5) which I tried once. A tiny tomato now has shriveled cotyldons. Does it go off after fifteen years? {LOL}

Linda

[Father'sDaughter]

Not sure what others do, but I actually fertilize ever time I water, which with DE is usually once a week. I use either Neptune's fish/seaweed emulsion or Urban Farm's vegetable fertilizer at half the recommended rate for seedlings. I also start fertilizing as soon as the seeds germinate.

[Labradors2]

Originally Posted by Father'sDaughter

Not sure what others do, but I actually fertilize ever time I water, which with DE is usually once a week. I use either Neptune's fish/seaweed emulsion or Urban Farm's vegetable fertilizer at half the recommended rate for seedlings. I also start fertilizing as soon as the seeds germinate.

Many thanks for the info. It's just what I needed to know.

I'm watering wrong too. I go around with a desert spoon and give the ones in soil-less mix a sip most days, sometimes more than once a day(!) That comes from my days of using peat pots. With the DE, I followed instructions and have waited until it turns white before watering, but I don't really know how much to give them and have had some explode with too much water. They're in pots made of newspaper, so that's not a lot of fun.....

Linda

[tnkrer]

Damping off in DE?

(obviously not blaming DE .. but trying to figure out if that is damping off and what I can do to prevent it)

[BigVanVader]

I finally got some DE and decided to do a little experiment on starting some Pink Brandywine's really early to sell at the market in the spring. They have done wonderfully, here are a few pics. The seeds were planted on the 1st of November and we're up by the 5th.

Second pis are on 12/6 just before I applied urine diluted 10/1; and the last are from today. I have been amazed by how well this works. Thanks again to all of you here for all the knowledge.

[Mark0820]

Originally Posted by RayR

Just for fun I tried a side by side comparison growing onion seeds in it and DE. I was actually surprised that the onion seedlings germinated and grew in such an adverse PH situation, but they didn't do very well compared to the onions in the DE. (See picture, this was at 30 days from seeding)

Ray, thanks for starting this thread. I never would have thought of using DE for starting seeds. The pictures of the root growth on the seedlings are impressive. I've enjoyed reading and learning from this thread. I think I will try this method in 2015.

I don't want to get off topic, but I saw your onion seedlings, and wondered if you could give me a few tips on growing onions. I have never had much success growing them. All I ever get are a few small onions. Would you mind using one post to give me a few tips for growing large onions?

[RayR]

Originally Posted by Mark0820

Ray, thanks for starting this thread. I never would have thought of using DE for starting seeds. The pictures of the root growth on the seedlings are impressive. I've enjoyed reading and learning from this thread. I think I will try this method in 2015.

I don't want to get off topic, but I saw your onion seedlings, and wondered if you could give me a few tips on growing onions. I have never had much success growing them. All I ever get are a few small onions. Would you mind using one post to give me a few tips for growing large onions?

For onions make sure you are growing a variety that is suited for your area. Since you are in the North, only grow long day or day neutral varieties. Short day varieties for the South won't make large bulbs up North. If you are growing from seed, start them early, they grow much slower as seedling indoors under lights. I typically start as early as the beginning of January. Consistent moisture and fertilize them well. Don't crowd the seedlings, separate the strongest seedlings into separate cells for faster growth. Plant out in early spring when you can work the soil and fertilize, onions are hungry plants. Plant in a area that get lots of direct sunlight, that's critical. Watch the weeds, onions don't like the competition. That's pretty much it, they'll grow pretty fast when in the ground outdoors and you should get some good size bulbs in summer.

[Labradors2]

Originally Posted by BigVanVader

Second pis are on 12/6 just before I applied urine diluted 10/1; and the last are from today. I have been amazed by how well this works. Thanks again to all of you here for all the knowledge.

Wow! 10-1. I'd have diluted it 20-1 for little seedlings, but they look fantastic!

Thanks for sharing!

Linda

[BigVanVader]

Yea they are doing great and I haven't fertilized them since I last posted. I normally only fertilize my plants if they look like they need it and I like to let my tomatoes wilt a little before watering.

[svalli]

Is the DE, which is sold in USA light weight or heavy as normal gravel?

I have had good results with the red color Danish moler granules, which are expanded and light weight. Only problem with it is that it is only available as cat litter and it has been scented and talcum powder added to it. Rinsing the scent and talc away uses a lot of water.

Now I found an other similar product, which is sold as anti-slip gravel for icy pavements. It is light weight and light gray in color. The packet say that it is "Natural product extracted from volcanic subsoil" and it is expanded silicate.
http://www.chr-olesen.dk/#!ecogrip-binder/c16so
Danish MSDS:
http://www.harald-nyborg.dk/pdf/3293_140017.pdf

The website also says that it can be used to absorb oil and chemical spills, even here in Finland it is sold mainly as anti-slip agent. I cannot find anywhere where this is mined from and wonder if this could be same or similar as the AutoZone DE.

Anyway I am going to give it a try for seed starting. If it does not work, I can always keep on rinsing the cat litter (I do not let our cat use it first, so rinsing is just to remove the floral scent ).

Sari

[RayR]

Originally Posted by svalli

Is the DE, which is sold in USA light weight or heavy as normal gravel?

I have had good results with the red color Danish moler granules, which are expanded and light weight. Only problem with it is that it is only available as cat litter and it has been scented and talcum powder added to it. Rinsing the scent and talc away uses a lot of water.

Now I found an other similar product, which is sold as anti-slip gravel for icy pavements. It is light weight and light gray in color. The packet say that it is "Natural product extracted from volcanic subsoil" and it is expanded silicate.
http://www.chr-olesen.dk/#!ecogrip-binder/c16so
Danish MSDS:
http://www.harald-nyborg.dk/pdf/3293_140017.pdf

The website also says that it can be used to absorb oil and chemical spills, even here in Finland it is sold mainly as anti-slip agent. I cannot find anywhere where this is mined from and wonder if this could be same or similar as the AutoZone DE.

Anyway I am going to give it a try for seed starting. If it does not work, I can always keep on rinsing the cat litter (I do not let our cat use it first, so rinsing is just to remove the floral scent ).

Sari

The DE that we are using in the USA is very light weight as it was formed from nearly pure Diatom sediment in ancient inland fresh water seas. Danish moler I understand is DE that has a high content of mineral impurities, mostly iron which gives it a darker color.
Any absorbent that is from volcanic subsoil is going to be Bentonite or Montmorillonite clays, which are much heavier than DE. If you can test the PH that would be helpful to see if it's in range for good plant growth. Some of these clays can have a high salt content too depending on where it is mined which would be a problem. Good luck experimenting!

[svalli]

Thanks Ray,

I got bag of the EcoGrip and tried wetting it. It does not get soft and break when wet like cat litter sand made from bentonite or montmorillonite. It is so light weight that it floats compared to the moler which sinks. I also tested its wicking properties by putting it dry into a small cup with holes on the bottom and watered via a tray underneath. It got wet on the surface quite quickly, while the moler in the other cup stayed dry.

The Danish MSDS says that pH is 7-8 and my soil test kit showed about 7 when mixed the granules and fine dust from the bag to the test solution.

So far it looks good except for the floating, which may cause some trouble for watering. If it does not work for seed starting, I maybe able to use it in soil mixes instead of perlite, so it does not totally go to waste. Price for this was also lower than perlite, so it could be an economical substitute.

I heard that some people had found unscented moler cat litter here under an other brand name. If the EcoGrip sand does not work, I have now more options for the seed starting.

Thanks to this discussion, which encouraged me to experiment with the cat litter, there are now many home gardeners in Finland using the cat litter for starting seeds and rooting cuttings. I wonder when do the gardening supply companies find out about this stuff and start marketing DE under their own labels.

Sari

[RayR]

If the EcoGrip floats then sounds like it is more like volcanic pumice. I agree that if it doesn't wick well, then it may be better used in potting soils for aeration.

[Mark0820]

Originally Posted by RayR

For onions make sure you are growing a variety that is suited for your area. Since you are in the North, only grow long day or day neutral varieties. Short day varieties for the South won't make large bulbs up North. If you are growing from seed, start them early, they grow much slower as seedling indoors under lights. I typically start as early as the beginning of January. Consistent moisture and fertilize them well. Don't crowd the seedlings, separate the strongest seedlings into separate cells for faster growth. Plant out in early spring when you can work the soil and fertilize, onions are hungry plants. Plant in a area that get lots of direct sunlight, that's critical. Watch the weeds, onions don't like the competition. That's pretty much it, they'll grow pretty fast when in the ground outdoors and you should get some good size bulbs in summer.

Thanks Ray! In the past, I had partial sun and partial shade. That must have been my primary problem.