Battle with brassicas

Can anyone advise??

Moved house last year and nothing apart from grass had been grown in the garden for years.  The soil is good, but full of bugs etc. (which the chickens have been removing for me).  Most things (especially fruit have grown well).  However spouts and other brassicas have failed.   I am wondering if this is to do with the acid soil (which chicken poo will make worse).  Wondering wether  to lime the soil - or go with raised beds.   Any advise on sprout growing would be good, cos I just cant seem to grow them!!!

And leave plenty of room between your sprout plants.  OH told me to put mine closer together this year to get more in, but you need a magnifier to find them, the sprouts are so small!!!!!

last year i grew them in a row and lost a good half to the wind (not that type of wind)
this year i have grown them in a block of about 20 they are doing fine about 400mm apart or 16"  may be a bit close cus they are touching each other now ,in the summer they were covered in white mites but the cold has shifted them ,still got to pick some maybe this weekend .