It all depends on how much asparagus you feel like eating .
We are a family of three,,, two adults & one mid tens teenager . There are 16 male plants in the bed this year will be the fourth year its been planted . The bed is about 5 x 5 foot square
Last year we barely took 10 reasonable sticks cut with a high grade bread knife wavy edge type that was cut with an angle grinder & fine blade to shape & then bent under heat to the asparagus knife style blade . This year production after the first liquid feeding in the third week of March should be a lot better , I hope to cut mid April till mid June
" how many asparagus plants should I grow per person ? "
Put that into Google & stand by to be amazed & /or ready to start grafting hard to get the bed raised & well made . If you can only plant male plants as growing berries like a female does takes an awful lot of energy.
I grew all my own plants from seed throwing away in the second year all those plants that bore berries . I then waited another year till I had 3 year old crowns in the spring before planting properly in the carefully made bed .
NB
Young asparagus seedlings look much like grass /weeds & die very easily if sprayed with round up ....... guess how I know ?
My asparagus bed would have been seven years old by now if I'd realised that .
In early November last year 2016 I gave it a 3 inch thick winter mulch coat of home made compost & home made compost manures well mixed up . Next week we will give the bed a light sprinkle of cooking salt to kill off perennial weeds that get blown into the bed .