Turnips

I never have much luck in the spring with them.  It always seems to go suddenly hot and they bolt.   Sown late summer they do well for me.  Usually I sow 6 or so seeds in a module and plant them out in clumps.  They need covering with netting on my plot or the pigeons munch them, but otherwise fairly trouble free.

As to varieties, I just buy seeds if I see them at a good price and go with them.  I’ve not found any one better than the other for basic white turnips 

I've always grown a swede variety called 'Marian', always tasty, grow to a decent enough size and usually get at least 2 crops a year with succession sowing.