Question
I am trying to find out what plants would be best to put in urns at a cemetary.  There is no shade and they would only get watered once a week unless it rained. The urns do not have holes in the bottom for water to drain. I want to find something pretty.  Anything so far that I have bought and planted has not survived more than a week or so.  Do you have any suggestions?

Answer
There is a basic problem with the urns that you discribe. In a word it is "water". It is the thing that most commonly kills plants, either by too much, or too little. In the case of your urn, it is in need of drainage. If the water sits in the soil, and can't drain out, the plants will rot, become diseased, or drown. The other problem is that the plants are sitting in the hot sun for a week, until they get water. They are getting too much, then too little.  So your question is, what kind of pretty, long blooming plant will survive for more then a week under these less then ideal conditions? The list narrows to imitation, or something close. There is a way to grow pretty flowers, in full sun, in a container, but not under the conditions you discribe. The fact that you have not had any success, is also proof of what I am trying to say.
My suggestion is, find a container with drainage. Add water retaining granules to the soil. Water the soil as weather and temperature require, which may be every day. Use annuals for their long bloom time. Replant them if they become unsightly.
But if this is not something you can do, then I recommend finding some pretty, easy care, plastic flowers that look real, and will stay attractive year around.

bakerplanter