Why do I have no luck with root veg?

[green lily]

Antipodes I usually 'thin' my root seeds with bonemeal as I sow. That helps the roots but not too much nitrogen. Also are you thinning and watering  them enough, remember they need space to grow and like to grow quick.

[green lily]

[strawberry1]

I am having real problems with swedes, the tops have all been eaten down to the ribs. So annoying, I am minded to pull them out and start again using the mound method, in a different place and using a fine mesh pop up cage that I bought. Any other help is welcomed