I would set up a system encorporating short diameter spray nozzes like this:

http://www.hummert.com/catalog.asp?C=65&SC=17&P=10402

This is what I use for my beds:

http://www.mortonproducts.com/page.cfm/1280

I use the red nozzles pictured because my beds and tables are 3 feet wide for ease of servicing. Red is a finer mist than is normal for actual plant irrigation but there are other sizes with higher flow rates.

I would also consider simply burying a 1&1/2-2"pipe horizontally with both ends sticking up shaped like this:

:____________________:

with 1/4" holes facing every plant and then fill to the rimm once per week or so with a garden hose or a automatic valve using a drip tube hanging down inside one end of the pipe. the trick would be to get the fill time right to avoid wasting water due to spillage.

Make sure you cap the ends of the pipe with wire screen to keep critters out, and remember you do NOT want this pressurized!

I am actually planning to try this in my nursery. It is a modification of age old wisdom known as clay pot irrigation and deep pipe irrigation in the more modern times.

Anyway that is my 2 cents worth... Good luck!