We plant beet every year and plant as per trunips, in a watered drill and cover lightly with soil normally mid may for harvesting very late Oct onwards, they grow rubbish in a dry summer and rot off if its a really wet one!
We have also found rabbits adore them!
We use an shredder which was here when we bought the farm, see here
http://www.cheffins.co.uk/lot/-108421-vintage-0 it is brilliant in winter it does beets and all root veg + apples & pears and in summer we put courgettes, marrows etc thro it.
HTH
Mandy