Using birdbath/fountain as planter.? I have a broken fountain that I be going to convert...

I have a broken fountain that I be going to convert into a birdbath but now I'm thinking of using it as a planter. I regard that some type of cascading or trailing flower might be interesting. I'm concerned that it might be too unsettled in the season to start from seed. Are there any variety that might work or should I try to find plants that have already be started? What are your suggestions? I live in Missouri.
Answers:    That seem like a pious idea, but my solely concern would be that the soil would have no opportunity to drain, plants contained by planters and in the ground enjoy a chance to drain any excess river, but there couldn't be drainage contained by a solid bottomed birdbath.
EDIT: OH! Well since it can drain, then if you want to travel tropical like, ferns would look honest, they have shallow roots too, or a nice trailing plant is the Edging Lobelia, or "Lobelia erinus", its get deep blue or indigo flowers, for that "hose down falling over the edge" kinda look :)
Other cascadings are:
Black-eyed Susan vine (Thunbergia alata): Vigorous yet transparent climber that twines through a container planting adding layer of flowers and foliage. The most common one have bright yellow flowers next to dark, almost black eyes; newer mixes very soon offer shades of red to purple.
Other: Species and cultivars of cup and saucer vine (Cobea), glory flower (Eccremocarpus), morning glory or sweet potato vine (both Ipomea); parrot's beak (Lotus berthelotii), million bells (Calibrachoa), and petuni
I would plant ivy surrounded by it. Then, if you want to plant something with color during the summer, you can slip contained by a few trailing blooming plants.