[nwalch]

I've never understood why the spacing given on say a seed packet is different to the distance between the rows (perhaps for tall plants like beans but not for say carrots\parsnips etc). If they can happily grow 8in apart in one direction why do they need 18in the other way?

What about with raised beds. Can you plant them closer together (if so what’s the best way to work out the distance).

[muntjac]

its 18 inches so your able to hoe inbetween the rows

[noshed]

Neither can I really but you can plant thing closer in a raised bed. You're supposed to add the two measurements together and average them out, or in other words, guess roughly.
All you need to be able to do is weed and allow enough room for the bigger things. I always plant everything too close together but all you need to do is eat every other one and it improves things.

[Aidy]

its 18 inches so your able to hoe inbetween the rows

You must have a big hoe munty  

[Ice]

Dr Hessayon says choose dwarf varieties and plant closer together.  Can't argue with that.  Werks for me.