At Labour Weekend last year I ate purple asparagus at the Culverden fete and have never forgotten how delicious it was. The spears have less fibre than the green ones and are higher in sugar content. The whole spear can be eaten from tip to base. Pacific Purple is a new "super-sweet" variety, bred by Aspara , aspara.co.nz
If you like to plan for the future, and you have the space, you could plant an asparagus bed now and be eating asparagus in three years.
Asparagus can grow near the coast. It enjoys sandy soil and loves seaweed as a soil fertiliser.
You can plant asparagus seed - available from Kings Seeds - but it's more usual to buy crowns. The word "crowns" is a bit confusing. What you will be buying is a bag of white roots, all jumbled up like tangled string. These are the 1-year-old base and roots of the plants.
Because the asparagus bed needs to be undisturbed for some years, make sure you've dug it over well, added compost, and got rid of all weeds before carefully spreading out the roots of the crowns in rows 20cm apart with the growth bud pointing up.
In the third year, you can harvest finger-sized spears for about four weeks. In subsequent years you can pick for longer, until the spears look spindly. Then let the foliage grow.
Asparagus crowns will keep cropping for at least 20 years.