This year the stock tank has a definite lime green theme with elephant ear, 'Electric Lime' coleus, and lime green sweet potato vine. It's still pretty early in the year, so the plants, disregarding the coleus, are pretty small.
I bought all the plants in the tank for $16, I believe, because I already had the sweet potato vine from overwintering. I bought 18 four inch pots of the coleus at $0.50 each, and I got 4 elephant ear tubers for $7. The coleus was the bit that worried me as it was beginning to bolt.
Since being planted in the tank, the coleus have cooled their breeches and are enjoying the good life. I'm guessing they were bolting due to stress and pessimism. Of course, it probably doesn't hurt that I've been going out pinching the growth to fill in the tank fully with beautiful moundy goodness.
The sweet potato vine is very, very small right now, but it grows ridiculously fast in the tank and will soon create a bib of lime leaves around the front which is part of "the vision" - the colors will go from lime (sweet potato vine) to variegated lime (coleus) to green (elephant ear).
The really strange thing is I don't much like the tropical look, but inevitably my tank looks tropical. Perhaps it's because tropicals can go from nothing to really big in a growing season?
What annuals are you growing this year?