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.

[Tracydr]

Having trouble keeping the soil moist. Any recommendations? I'm thinking about sprinkling a bit of peat moss on top,

[b54red]

Originally Posted by Tracydr

Having trouble keeping the soil moist. Any recommendations? I'm thinking about sprinkling a bit of peat moss on top,

Are you using Ultrasorb? Are yours outside where the wind and sun can evaporate the moisture too fast?

If you are starting your seed outdoors then I recommend setting your cells in a tray that has some water that can be pulled up. Whenever they start looking too dry then just add more water to the tray. I don't like to do this here because of the damping off problems in our very humid climate but that shouldn't be as much of a problem for you.

As soon as you get a few good true leaves go ahead and pot up into larger cups that are easier to water. I just use regular potting soil for this and not DE.

Bill

[Logrus9]

I read the entire thread a few weeks ago and decided to try it. It worked almost too well for tomatoes, peppers and squash especially. Almost all of them had roots growing through the fiber pots by the time the second leaves came out. This is my first time sprouting seeds so I thought I would have more time, now I'm scrambling.

My Uncle is 90 and he thought I was as crazy as a bedbug when I told him what I was doing, he doesn't say much now.

[zeroma]

I can hardly wait for when I pot up to see the root growth. Ran out of time for doing that today. But most of the seedlings that have their first and second leaves look so healthy.

The set of trays I started a week or so later are looking a little less green. They were left on the heating pad a bit longer than the first trays got a bit leggy. Now they are under lights and their stems are getting thicker and looking better.

I love this DE for starting seeds.

[b54red]

Just remember not to leave the seedlings in the DE too long without some fertilization as it doesn't supply any.

[Logrus9]

Yes, the next batch I plan to try a dilute solution after about 10 days.

[RayR]

I accidentally discovered another benefit of DE the other day. Last week there one night where the temps dropped below freezing and I forgot to bring my onion seedlings into the garage. Most of the onions were in small 3" or 4" pots and to make things worse they were on a table outside. Would have been better if they were on the ground. The onions were in a variety of mixes, some straight DE, some straight Jiffy Mix, some in DE/Coir and some in DE/Jiffy Mix.
The next day the top growth looked a little frostbit, but otherwise alive.
A couple days ago, the weather was nice and soil was perfect for planting so I decided to get some onions in the ground. When separating the seedlings out of the peat based Jiffy Mix I discovered root damage, like the roots fell right off and were more dark in color, but the seedlings in the straight DE and the DE/Coir mixes had perfectly healthy white roots. The DE obviously insulated the roots very well from the worst of the freezing temperatures, where the peat did nothing.

[livinonfaith]

I absolutely loved potting up from the DE to potting soil.

When potting up tomato and pepper seedlings, I kept a bucket of water at my feet. I would push the plants with their hunk of DE out of their container, then dunk it in the water and swirl it around. The DE would easily swirl off and I was left with a bunch of little plants that practically fell apart. There was very little pulling or prying required.

It certainly seemed like there was less root damage with this method.

[b54red]

Originally Posted by livinonfaith

I absolutely loved potting up from the DE to potting soil.

When potting up tomato and pepper seedlings, I kept a bucket of water at my feet. I would push the plants with their hunk of DE out of their container, then dunk it in the water and swirl it around. The DE would easily swirl off and I was left with a bunch of little plants that practically fell apart. There was very little pulling or prying required.

It certainly seemed like there was less root damage with this method.

That is a very good idea. I never thought of it. When the DE is dry there is no problem separating the plants but when it is too damp the roots cling together much more and dunking them would just wash away the DE.
I've got some plants that need potting up today so I'll get to try it. Thanks.

Bill

[zeroma]

I potted up 1 of my flats last night too. The DE very wet worked wonderfully. First, I filled the 4 inch pots with wetted Pro-Mix, made an indentation with my soup spoon in the centers. Placed the marker in the pot, and simply scooped the whole plant into the spoon, plopped it into the indentation, leaving all the wet DE around the great looking root ball, and filled in with more moistened Pro-Mix. I placed all the 4 inch pots into a tray of water so that they would wick up more water.

I'll never use potting mix/seedling mix again. I didn't have even one die from damping off. I did have several headless stems and I culled them. I did accidently remove one of the sprout leaves when I was helping the seed coat come off, and it died on its own.

I left them all night in their new pots on my kitchen island in the dark. This morning I moved them to the shelving with the lights. They look happy.

[RayR]

I tried a number of DE mixes with organic components
Mixes of Optisorb with GH Coco-Tek Coir I liked the best. The coarse texture of the coir complemented the medium sized diatomite aggregate of the Optisorb nicely and was easy to work with. Results in germination and growth were excellent. I'll be potting them up this weekend.

In this tray of Tomatoes there are 24 varieties with 2 different mixes, seed sowed on 4/1:

50% DE / 50% Coir
50% DE / 40% Coir / 10% Screened Worm Castings

In general there are more seedlings in the mix with the worm casting that are little larger than the seedlings in the 50/50 DE/Coir mix. The magic of worm castings?

Nutrients and supplements used up to this point were from the General Organics Go Box (BioThrive Grow, BioRoot, CaMg+, Bio Weed, Bio Marine), also Roots Organics Trinity was used when adding inoculants (BiotaMax and AZOS)
They also got one watering with freshly brewed compost tea last weekend.

[greentiger87]

What really shocks me is how well the seedlings transplant. And I'm talking about very disparate kinds of plants, many which *hate* being transplanted to begin with. I'm always afraid when I see those bare, naked white roots... I especially worry about how to make sure they're spread out in the new soil, rather than all squished together. But even when I transplant in a rush.. basically just dumping the seedlings in with new media.. they magically don't even wilt ?!

I'm not really sure how to explain that. I've been giving away so many seedlings this year because I greatly underestimate how many will survive.

[Father'sDaughter]

Originally Posted by greentiger87

What really shocks me is how well the seedlings transplant. And I'm talking about very disparate kinds of plants, many which *hate* being transplanted to begin with.

I've noticed that as well. It used to be that when I potted up, growth would stop for at least a couple of days while the roots got settled in their new home. Going from DE to potting mix this year, the seedling just seem to start growing overnight! In less than a week after up-potting, my tomato seedlings more doubled in size

[RayR]

I guess a good theory is that it's not disturbing the roots that causes either transplant shock or stalling of top growth for a few days. Pricking out seedlings from soil and separating them when potting up causes damage to the roots, where in DE there is little to no damage to the roots when potting up.