Hi kimisue, Welcome to GW and to gardening!
I'm a bit southward of you so I can't suggest any good plants. I always suggest that folks check out their local "mom and pop" nurserys to discover good plants for their gardens.
However, I will suggest that you find a nice pot for the mailbox garden. From your description of the soil, a container garden will be a lot easier and quicker too. The main disadvantage to container gardens is that you have to water them more often, and some containers are pricey.
I've had good luck with container gardens in the "disadvantaged" areas of my yard. ;-)
Hope that this helps, Good luck and happy gardening.
Cindy

I too don't know what to suggest for plants but I would like to mention that you should also think of your mail carrier. You may not want to plant something that attracts a lot of bees and wasps. I don't have anything planted around my mailbox and on more than one occasion I have opened my mailbox only to have some wasps fly out. I wonder who would be responsible if a mail carrier got stung and was allergic. hmmmm

JP

I don't live in your area so I can't give suggestions on what to plant. I am however a mailcarrier and would like to tell you to keep in mind the area that the carrier pulls up to------you should be able to tell by where the area is worn. We do need to get close!!!!! Oh, and yes I just love all the bees, wasps , spiders and such that love to surprise me. Let me just say all carriers are used to it and it is basically a part of the job ( have been stung many times!!! ) The main thing that you should keep in mind is don't plant anything that will grow directly up and around the box. Many people plant clematis in my area which are beautiful near a box. If you plant a vine type plant PLEASE give it a trellis behind the box to grow on. It helps keep the bees and such a distance from us and also does not cause problems getting in and out of the box once it is full grown. As a carrier I can tell you I really enjoy pulling up to a box that is landscaped as it gives me something to enjoy on my drive-----even if I do have to deal with a few critters, but then again I am a gardner too so the view for me overrides the critters. Ask your local nursery for suggestions ------- and pay attention to what others have in your area around their boxes to see what is growing for them. Good luck and happy planting!!!!

Thank you all for your replies. As for the vine type plants, I dont think they would work well for my mailbox and I also dont think I have quite the skills to be able to grow a vine plant yet having to trim it back and all. I was given the suggestion of the Madagascar periwinkle (Catharanthus roseus) and was wondering if any of you have any experience with this plant. It is suppose to only grow to 1-2 feet tall and the same width, which would still put it under the height of the actual mailbox.

Kimisue,
The Madagascar periwinkle should do very well for you.
(No containers and fancy potting soil needed for these tough customers!) In my area they grow in the cracks of the sidewalk, almost like a weed. Infact, they are invasive in some areas. But they are pretty plants with lots of nice blooms all summer and fall and are easy to pull out if they reseed too readly. I've seen them in shades of white, pink and purple and they do seem to grow about 1-2 feet.
Good luck and happy gardening.
Cindy

Lantana and ruella can stand bad soil and the heat. Perhaps moss rose/portulaca or the different varieties of zinnias and cosmos would do well there too...

I have Gaillardia (Fanfare) around my mailbox. It comes back every year and is drought tolerant. Any of the gaillardia should be about the same since they are a native plant and drought tolerant. Try a sedum also since they take less water. Lantana and the moss rose/portulaca are good ones too. The lantana will come back every year but not the portulaca. Good luck!