under fence plants

I'm not sure what to plant underneath the bottom rail of my white vinyl split rail style fence. I would prefer maybe a variety of plants that would bloom or at least show some color through out the seasons.
I would like to keep the plants short as to not cover the bottom fence rail, which is about 12"-14" from ground. The spacing between each post is about 5 1/2'. Total fence length is roughly 220'.
Any help would be greatly appreciated.
Thanks
Ghibby

Not too sure about the soil you have at the fence, (dry, damp, fertile, stoney, poor, shaded, full / part sun) so you would need to take all that into consideration when it comes to selection of plants.
There are hundreds of LOW growing plants that would fit in with the height of the bottom of the fence but most would prefer good light.
If your talking about Perennial plants (come back year after year) I would be looking for things that are suited to ground cover, IF you want Annuals, (plant seeds and they grow / flower same year then die off) both COULD cause problems, the Perennials will after a few years spread out naturally, this may cause them to encroach onto the other side of the fence and IF you have neighbours, they could dig them up, weed kill or whatever, the Annuals will do what nature made them to do, that is spread their seeds far and wide,
Also take into consideration, this will be a difficult area to look after, I*F you don't constantly care for it with regarding plant growing, I know every fence we ever erected had a profusion of weeds growing in the most difficult places to remove them.

Plants to look up and consider.
Ajuga
Aubriieta
Dianthus
Phlox
Sedums
Vinca (spreads)
Hosta
Geranium (Perennial)
Polygonum (Different plants / height)
Thymes
Veronica.
All the above are perennials and there is many more.

Annuals / Per-annuals. all from seeds.
Alysum
Begonias
Viola
Tagetes (French / Mexican Marigolds)
Poppy's
Nigelia

All can be grown in situ from seeds sewn in early spring, plus many more.

There is also many SMALL mini evergreen Shrubs that I wont go into now as you really have not given enough info as to how much time you can spend looking after the area, do you want to widen the area to say 3-4 feet wide border, much better and easier to look after as you have room to grow better selection AND room to look after the ground / plants.
Hope this gives you food for though and ideas.
Best Regards.
WeeNel.

Thank you so much WeeNel, for your help. I think i will be able to figure it out from here. You sound like a very knowledgeable person and next time i will try to be more specific.
Thanks again
Ghibby

Your Very Welcome Ghibby, hope it all works out for you and you have a lovely show of the plants of your choice.
As regards knowledge, I have been gardening for more years than I care to tell however. as with All people who garden, there are always things you learn and from one continent to another, it appears Gardeners love the share their knowledge.

Stay with us all on the site and you will find LOT'S of other who will be glad to help you out also.
Kindest Regards.
WeeNel.