Hi, we travel frequently, so we have all of our gardens, beds and greenhouse on drip systems. They work well and are all automatic. We get most of our drip parts from big box stores like Home Depot or Lowe's. They are also available online from irrigation supply places. Here is an article to help:
http://www.lowes.com/projects/...
If you put in a drip setup you'll come back to your flowers doing really well. If you have a neighbor who could check once in a while to make sure all looks good, that would be even better. On occasion we have had drippers plug up, or get blown out of the proper position by winds.