I've had a breakthrough this year on the brassica growing front and having got sprout plants particularly like I've never seen in 30+ years of gardening, I felt it is worth passing on what seems to have made the change.
Brassicas as all gardeners know suffer attacks on a number of fronts and H &S have taken away most of our defence chemicals. Cabbage root fly is the first attacker - can be got round with collars round the young plant stem, but that's tedious to fix and costs. Slugs and then cabbage white butterfly caterpillars are the next two assailants, and if you are unlucky like me and have the clubroot fungus in the soil too, you really are stuffed.
The clubroot I seem to have solved by growing the plants in 50mm plug seed trays,but having found that wasn't totally reliable previously, this year I trowelled out a vaguely 75mm hole in the ground, filled that with JI2 compost and planted the 50mm plug into that. Not one plant in around 100 has failed this year.
The other real winner was to cover all the plants with fleece - reasonable quality stuff, not the 'shed' grade. I guessed this would keep the root fly and butterflies at bay, but there's no slug damage either and what I didn't know is that fleece raises the temperature under it by a couple of degrees C, so all the growth has been so much better.
OK one year's results aren't that good a statistic, but if I get the same next year I can reduce the number of plants as the yield is now higher than we can consume.