Diatomaceous Earth as a seed starting medium

[JamesL]

Originally Posted by Rairdog

I put the used DE in the microwave for 3-4 minutes in a glass bow when barely damp. Then I check it to 180.

I started over 500 plants in DE so far this year with over 90% germination and no damping off at all. That includes:

Pepper - Cal Wonder, China Giant, Anaheim, Greek pepperochini, Corno di toro, Serano, Orange habanero ( I have 72 super hots germ. now)

Tomato's - Martino Roma, Pineapple, Cherokee Purple (I planted another 72 of various varieties yesterday)

Baby Bok Choi, Muchilini Cabbage, Spinach(2 types), Kale, Chard, Lettuce (4 types), Kohlrabi, Lime Basil, Common Basil and Butterfly weed

Celery was a bit of a problem but it was my fault with moisture.


Here are some random pics. Everything was started in DE except for flowers.



Fig was propagated in DE but is in soiless now with DE topping. The butterfly weed next to it was also started in DE. I am working on Goji Berry now and will try other berry propagation throughout the year.



The BEST part...it is super easy to shake off the DE when you let it dry out for transplanting to my aquaponics system. No more rinsing and soggy roots. There is also less shock. Here a a shot of one of the AP beds. They took off much faster than previous years.

Overall shot of the GH.

Thanks Ray!

Rairdog,
Great pics and nice setup!

[Father'sDaughter]

Somewhere in this monster of a thread there is a post about sterilizing DE for re-use. I made a note for myself because I knew I'd never find it again!

Spread it out on a baking sheet and place into a 400F oven for 30 minutes.

There was also discussion about whether or not it should be rinsed prior to baking (to eliminate salt build up, I believe). What I remember is that if you are only using organic fertilizers, this wasn't a concern.

[b54red]

I think this thread should be make a sticky thread. It is one of the most informative and helpful threads especially for those seed starters having trouble with damping off.

Bill

[tnkrer]

Originally Posted by RayR

Thinking about where the Pythium or whatever spores came into the picture since the DE is sterile out of the bag.
What is your water source that you used?
Did you sterilize your seed trays before filling them?

How warm was the soil on the heat mat?

Water source is city water. Next time I will make sure that I use the filtered city water (that we use for drinking, filters the water using GE FQSVF filter)

Did not sterilize seed trays only lightly cleaned after last year's use. So now a bunch of seed trays are in 10% bleach solution. I will take those out after an hour, air dry them and remaining seeds will go in those

Have not measured soil temperature. The air temperature in the seed tray + plastic enclosure stays between 70-80.

I am letting the DE almost dry out before adding some water to the bottom tray instead of keeping water there all the time

Lets hope that sterilizing the trays solves my damping off problem

[Rairdog]

I keep a five gallon bucket of bleach water on hand. All the small stuff that fits goes for a dunk before use. I keep a spray bottle of bleach water for spraying the bigger stuff. I keep a bottle of 1 to 10 3% hydrogen peroxide on hand to spray the top of any media when I see brown/green algae or white mold/fungus. If the media has been damp on top and humidity is high, I will do a preventative spray.

[Worth1]

Originally Posted by Rairdog

I keep a five gallon bucket of bleach water on hand. All the small stuff that fits goes for a dunk before use. I keep a spray bottle of bleach water for spraying the bigger stuff. I keep a bottle of 1 to 10 3% hydrogen peroxide on hand to spray the top of any media when I see brown/green algae or white mold/fungus. If the media has been damp on top and humidity is high, I will do a preventative spray.

And you dont have damp off problems do you.

Worth

[HeatherT]

OK, I made it through all 771 posts in this thread, lots of good info here to be sure. I went to the local Auto Zone and picked up a bag of DE and filled my 3.75" net cups and planted five different tomatoes and nine different pepper plants. Placed the cups in a 39"x19" fiberglass tray (no humidity dome) and filled with tap water that was left for 24 hours to help remove the chlorine, keeping ~1/2" of water in the tray. I planted the morning of 3-24 and as of yet no joy, they are currently on the second floor in a south facing window. If nothing is up by tomorrow I will move them to the basement and put them on a heating mat, once I have germination they will move to a second tray and go under a 400 watt metal halide light with a fan to simulate outdoor conditions. In the end these will be planted in a hybrid RGGS, this will be my first experience using this system but I have high hopes.

Heather

[Father'sDaughter]

Originally Posted by HeatherT

OK, I made it through all 771 posts in this thread, lots of good info here to be sure. I went to the local Auto Zone and picked up a bag of DE and filled my 3.75" net cups and planted five different tomatoes and nine different pepper plants. Placed the cups in a 39"x19" fiberglass tray (no humidity dome) and filled with tap water that was left for 24 hours to help remove the chlorine, keeping ~1/2" of water in the tray. I planted the morning of 3-24 and as of yet no joy, they are currently on the second floor in a south facing window. If nothing is up by tomorrow I will move them to the basement and put them on a heating mat, once I have germination they will move to a second tray and go under a 400 watt metal halide light with a fan to simulate outdoor conditions. In the end these will be planted in a hybrid RGGS, this will be my first experience using this system but I have high hopes.



Heather

They just need a couple more days. Mine were started in DE on 3/22 and they just started popping up last night. No heat mat.

[Pegasus]

Could it be the the de is mostly calcium is that not the shell of the diatom animal just a thought
cya Pegasus

[RayR]

Originally Posted by Pegasus

Could it be the the de is mostly calcium is that not the shell of the diatom animal just a thought
cya Pegasus

DE is almost entirely amorphous silicon dioxide. Diatoms make their shells from disolved silicic acids in the water, not calcium. Any other minerals present are in trace amounts.

[neoguy]

Just a bump as it is seed starting time.

Any chance we can pin this?

[zeroma]

Originally Posted by b54red

I think this thread should be make a sticky thread. It is one of the most informative and helpful threads especially for those seed starters having trouble with damping off.

Bill

I wish someone would do a few summary type posts and then make a sticky...and then refer back to the original 771 posts for those who want/need all the information.

Just a thought for someone who is great at summarizing. I used DE and it worked great.

Zeroma

[zeroma]

Originally Posted by ChrisK

Adding another anecdote to this thread. The pic below is a comparison of my peat:perlite blend vs Ultrasorb. It's obviously way too small for any kind of statistical comparison. The same genotype from the same packet of seed was sown on the same day. Egg carton was then placed on my seedling heat mat until emergence was noted.

The ultrasorb plants emerged 3-4 days later and are clearly behind their siblings in the peat mix at this point.

So how did your babies do ChrisK?

Zeroma

[Father'sDaughter]

Originally Posted by neoguy

Just a bump as it is seed starting time.

Thanks for reminding me that I need to go buy a few bags!

[BigVanVader]

I started my peppers in DE again, some are already up. I think I will do a side by side with the Cal Wonder seeds I need to start. Half the seeds in a peat based SSM and the other in DE.