Seedlings are failing
I planted tomato and pepper seeds a few weeks ago. The peppers seem to be doing okay, but the tomatoes (4 varieties purchased through Territorial Seed) are all failing. Barely starting their first true leaves. I started them in coir (which I have done successfully in past years). Most germinated fine, but have now stalled. I added some diluted fish fertilizer with no improvement. I added some diluted worm casting (from my own worm factory compost system) and still no improvement. They get light through a window and have heat in the room (all the same as in previous years when things grew well). I put them outside in the sun for a while the other day, but still nothing. I’m not doing anything differently than in the past, and I’m not sure what to do. I would greatly appreciate any ideas. Tempted to just up-pot them in real soil to see if that helps, but afraid they are too puny to survive it.
Washington County Oregon
Thank you for your question about your seedlings. I apologize for the delay in answering your question, and hope they have survived so we can still discuss them!
I appreciate that coir is a popular medium for seed germination, and research has indicated it holds moisture well near the growing plants' roots. However, most of the science-related recommendations include combining it with equal parts of compost and vermiculite, as explained in this Extension article. I think one issue is inadequate nutrients near the roots (which the compost addition would solve.)
The other problem with your plants is that they appear to need more light. That's why many home gardeners invest in a grow light or grow strip, which provides the light spectrums that growing plants need. Often, those are filtered out by our energy efficient window glass.
I'm assuming (since you've had success in the past) that you're familiar with the process of vegetable gardening, but if you need a 'refresher course,' you can download this OSU Extension publication, and keep it for reference. Good luck!