Brassica seedling problems in soil blocks
This is my first year using soil blocks, and I love them. Tomatoes, peppers, herbs, squashes, melons, flowers, all have done very well. The brassicas, however, are driving me crazy. I've tried 3 separate attempts this spring. One was a mild success, and the others were total flops.
Here is what is happening. Germinating well, looking great until their first true leaves come out. Initially they look good, but then they seem to get stunted, and the leaves slowly start to turn yellow. Then the gradually shrivel up to nothing,
I'm growing them in a seed starting mix (Sunshine 360 or Pro mix) mixed with aged compost from cow manure (moo-nure from Home depot). They are definitely not too wet. After their true leaves emerge, I add fish emulsion weakly to the water. One fish emulsion I used was higher in P and K and N. The other I tried was maybe 4-2-1? I've tried inside and out, esp when the weather was cooler.
Any suggestions for me? I'd like to start another round for the fall. Maybe I should try some in soil blocks and others more conventionally?