Diatomaceous Earth as a seed starting medium

[Delerium]

I have been treating Tomato Seedlings like Rag dolls in DE and its impossible to kill them. I have chopped the tops off.. cleaned off rootballs to inspect roots. It's amazing what DE can do for you. RayR you would be happy to know that DE works pretty good for grafting applications as well. We need to give you the Nobel prize for finding us a cool new growing medium.

[RayR]

Originally Posted by Delerium

I have been treating Tomato Seedlings like Rag dolls in DE and its impossible to kill them. I have chopped the tops off.. cleaned off rootballs to inspect roots. It's amazing what DE can do for you. RayR you would be happy to know that DE works pretty good for grafting applications as well. We need to give you the Nobel prize for finding us a cool new growing medium.

Umm...if that prize comes with $2Mil, I'll gladly accept.

So when is the release of your next video? You left us hanging with the grafting when your battery ran out.

[Delerium]

Yeah I know. That reminds me I need to charge the battery. Hopefully this weekend i can shoot some video, and if my boss (my daughter) lets me work on the computer i might be able to get a video out by this week. It's amazing how fast toddlers learn. She has pretty much figured out how to use my Windows pc & is a pro using her momma's ipad 2.

[zeroma]

I potted up the second tray of seedlings yesterday. One of the egg cups had 6 seedlings but they all were in good shape! I did not do that on purpose, it just happened.

The roots were much longer that I expected they would be, some I ripped off (by accident) then I discovered that I could just invert the whole egg carton in the standard tray filled with water and swish them around until the roots seperated by themselves! Most all the plants I've potted up are doing well. Some have lost a leaf or two on this second batch, but then I fooled around more with getting the DE off the roots just to see if it made a difference.

The leaves are a purple color so I need to get some better fertilizer, not just the weak all purpose MG I've been using. I didn't realize it was a problem until I read someone elses post about purple leaves. It is at the top of my grocery list for tommorrow.

Next time I start seeds, I plan to start them in the larger yogurt cups I have been saving or pot them up much earlier from the egg cartons into smaller, 3" pots. I'm running out of growing room with going from about 35 of the 50 that germinated to a tray to only 15 of the 4" pots in a tray. It is all a learning curve. Just keep doing it until you get it the best for yourself I guess.

[zeroma]

I wonder if damping off would stay at bay as well if I were to fill the bottom half to 3/4 of a 4" pot with Pro Mix BX and the top 1/4 or half with DE. And avoid potting up completely????

Or making a 'nest' of DE in the middle of the Pro Mix???? Spout the seeds first on coffee filter, etc, place the germinated seed on the surface of the DE and just dusting over the top of the seed with fine DE?

Oh, wait I know. I will try this out with some of the seeds I'm sprouting now. Fill the 4 inch pot with dampened Pro Mix, make a tunnel all the way to the bottom with a spoon or something, moving the very center of the Pro Mix and dropping in wetted DE. Then place the seed on the top of tha.

Yeah, that's what I'll do tomorrow morning. I'm sure to have some more sprouts since I started them last week Sunday. By the time the seedling roots have grown to touch the Pro Mix, the period of damping off will have past? Do you think???

[RayR]

It's not unusual to have some seedlings with the purple color under the leaves, some varieties have it more than others, and some are totally green. They grow out of it, the purple will fade away slowly . When the plants are bigger and they have purpling, then it's usually a problem with phosphorus uptake, from cold soil temps, water logged soil or nutrient issues.

[Levent]

Ipomoea x multifida seedlings under lights.

[zeroma]

Originally Posted by RayR

It's not unusual to have some seedlings with the purple color under the leaves, some varieties have it more than others, and some are totally green. They grow out of it, the purple will fade away slowly . When the plants are bigger and they have purpling, then it's usually a problem with phosphorus uptake, from cold soil temps, water logged soil or nutrient issues.

Thanks RayR. 2 of the seedlings with only the seed leaves growing were totally purple and I thought they were so 'cute'. Since then, their true leaves are green. Wish I would have marked down which ones they were.

[beeman]

Well, I've given up on using Qualisorb, the Canadian DE available locally.

The seeds that sprouted never grew, even after watering with a weak fertilizer. So today I pulled out and potted up what I could salvage and there were virtually no roots. Just small stubs where they should be.

I have to wonder if the manufacturers might have added a growth suppressant of some sort as even algae hadn't started on the DE.

Disappointed, but not cowed, will try making and using soil blocks instead.

[RayR]

I can't imagine why they would add a algae suppressant to a DE oil absorbent.
The only thing that makes sense is the PH is way off from the 7.0 they claim.

[RickCorey]

Travis or anyone,
>> I'd really like to use something besides peat, vermiculite, perlite, and coir, all of which have posed various problems for me either with regard to cost, function, or sustainability.

I've started adding screened pine bark (or conifer bark) to my potting mix and seed-starting mix, to stretch it out, make it less expensive, and especially to make it faster draining and more ventilated.

I haven't tried tomatoes in it yet, but planned to make some 5 gallon buckets with a lot of bark nuggets, anything that passes through 1/4" hardware cloth. I'll have to be sure to have some fine fibers and/or peat to get more water retention and wicking, but I can run drippers on a timer if I need to.

Has anyon e had good or bad experience with bark in seed stratin g m i x, or larger containers?

[beeman]

Originally Posted by RickCorey

Has anyone had good or bad experience with bark in seed starting mix, or larger containers?

You do realize that Pine bark of any size is acidic? This might lower the Ph below the optimum for seed starting.

It's used extensively in Blue berry culture to lower the Ph of the planting mixture down towards the 5.0 Ph required by blueberries.

[RayR]

Right beeman, as been said many times before the PH of a seed starting medium is critical to how well the seedlings will perform. If you are making your own seed starting mix or using a medium that wasn't intended to be a seed starting mix and you don't know what the PH is, you're just taking a shot in the dark.

I've been potting up tomato seedlings and got a closer look at the comparison of growth in DE/Coir mix and the DE/Coir/Worm Castings mix.
The results were pretty much 90% consistent across the board with all varieties, the mix with 10% worm castings produced larger seedlings, both in height and stem diameter.
Here's looking side-by-side of cherry tomatoes (Isis Candy in the front), 50% DE/50% Coir on the right, 50% DE/40% Coir/10% Worm Castings on the left.

The second picture shows the roots of the Isis Candy plants from the mix with worm castings. I didn't get to pot up the plants in the DE/Coir mix yet so no root picture. Separating the roots was just as painless as with 100% DE.

Back to PH, I decided to check the PH of the DE/40% Coir/10% Worm Castings mix with my meter to see if it changed since the beginning of the month, PH came out at 7.1, so it didn't change much at all.

[natekurz]

Originally Posted by Tonio

Let us know if you find a source for the fine grain sized selectsorb. It may/may not be better for tender rooted plants.
They come in 20 &25# bags, wondering the cost difference.

I bought a 20 lb bag of Moltan SelectSorb today at Napa Auto Parts. Listed at $16, but charged $9.88 plus tax. Part #8892 "Floor Sweep".

Has anyone done comparisons between the different granular sizes of the Moltan DE products: SelectSorb (fine), UltraSorb (medium), and OptiSorb (coarse)?

[RayR]

Originally Posted by natekurz

I bought a 20 lb bag of Moltan SelectSorb today at Napa Auto Parts. Listed at $16, but charged $9.88 plus tax. Part #8892 "Floor Sweep".

Has anyone done comparisons between the different granular sizes of the Moltan DE products: SelectSorb (fine), UltraSorb (medium), and OptiSorb (coarse)?

I've never seen SelectSorb, it is supposed to be a fine granular, smaller than Ultrasorb. Could you post a picture of the stuff so we can see what it looks like?


Another thing about UltraSorb, I picked up a few 33lb bags of UltraSorb locally this past fall and the particle size is different from the smaller size bags of UltraSorb that I got from AutoZone. The size of the granules are in between the size of the UltraSorb from AutoZone and Optisorb.