Thanks, cakbu. Which sort of emitter do you think would work best? We are calling the irrigation guy today about a broken sprinkler head. I'd like to tell him to bring xyz emitters and install them while he is here.

Something like these: http://www.lowes.com/pd/Raindrip-10-Pack-Drip-Spray-Drip-Irrigation-Drippers/3407016

They come in various volumns of dripping.

Thanks! The irrigation guy is coming next week. I'll make sure he uses something similar.

Any Licensed Irrigation Contractor should know how to irrigate containers correctly using their drip zone as a water supply source. If they don't (and the info you supply indicates doubt) they only had to call their supplier to purchase/order the needed parts. Container Wholesale Nurseries use these same materials so it is nothing out of the ordinary.

A non reducing connection between the drip main line tubing and a length of spaghetti tubing is used. Putting a reducing emitter in the container only controls the amount of water to the container it does not distribute it across the surface of the potting medium. A 'spray stake' of the correct type is needed for that.

The irrigation guy is supposed to come this week. I'm hopeful he will install the correct fitting.