Dirty and stinkin': Damping off and self-watering fail

I am on high alert after losing two egg cartons' worth of seedlings in the germination / propagation station to damping off Thursday.

I think I figured out the causes of the seedlings' premature deaths this morning when I inspected some geranium and other transplants that I had set up last weekend to be self-watering: the area is too humid due to the water reservoirs, and the transplants' soil is a constantly wet. I don't sterilize my seed-starting mix and potting soil (although I do sterilize my pots and tools), so in addition to an ambient temperature that varies between 16 and 20°C, almost all of the ideal conditions for promoting fungal growth are there.

In fact, I saw this morning that the surface of the transplants' potting mixture was covered in tiny white specks, and there were fine white filaments coating the below-soil portion of the popsicle sticks that I was using as markers.

I'm not sure what I should do about this. Except for what could be attributed to transplant shock, the geraniums, potato vines, sedums, and unidentified herby greens look all right. In fact, the herby greens are thriving, if a little leggy from being so far from the light.

The Web did yield some non-chemical techniques for controlling fungus attack which I will be trying:

1. Let the soil dry out
2. Apply ground cinnamon (it's the brown stuff in the pictures above)
3. Water with dilute chamomile tea

In the long term, I will definitely be sterilizing my potting and seed-starting soil in the oven before using it. This involves baking it at no higher than 180°F or 80°C for 30 minutes.

But in the middle term, I'm sort of stuck for a solution to keep the plants in the propagation / germination station happy for all the weeks that I will be unable to water them. Clearly, the combination of medium (straight potting mix) and wick that I'm using in this self-watering setup is inadequate in that it's too moist, but I won't have time to experiment with this before I leave. I'm also wary of re-transplanting them into "clean" containers so soon after having transplanted them in the first place. Perhaps I should ditch the self-watering component, chance not watering the plants for the duration of my travels and let Darwin sort 'em out?

Some resources:

• NoDamp from PlantProd seems to be a popular remedy, but is apparently increasingly hard to find. Art Drysdale explains why (long story short: manufacturer was asked by the federal government to prove efficacy, which they declined to do)
• UMass extension has a nice fact sheet on damping off and an extensive list of chemical fungicides that can be used to control it;
• Dave's Garden also has a nice article on the dreaded damping off
• Organic remedies for damping off and other fungal diseases
• Organic and chemical remedies for damping off and other fungal diseases