How many days will you be gone?

Get yourself a small timer like you use for the Christmas lights and hook that up to a small water pump like found on one of those "water features" things you can set on the table in the living room. Give it a large supply of water via a 5 gallon bucket or larger and then put the output of the little pump into the bucket for the plant.

If you set it up to catch the runoff from the container, you will not waste any water and the plant will get a watering once a day or whatever you want. I saw one set up for a single plant that used a childs small plastic wading pool with a small bilge pump and a return water catcher. It was good for 2 weeks plus for a single plant.

Ted

You can buy ready to install small drip irrigation set-ups from many different sources. They are complete with timers, pressure reducer, feeder lines and drip emitters for approx. $50 or similar set-ups without the auto timer for any where from $15 to $25 if there is someone who can turn it on and off for you. Example of one below.

Dave

Here is a link that might be useful: Container drip system

Next time put the pot in a 5 gallon bucket or Aluminum baking pan, fill the space around the pot 1 inch for every day you will begone.
This work great for short span of time, no more then 5-7 days. As soon as you get home remove the pots from the water bucket. I have done this with Japanese Maples, fig trees,& many house plant in hot August heat of the South.