When it comes time to deciding which annuals to order for next year, Bird makes her selection based on the previous year’s sales and customer requests. Plant breeders are constantly developing new varieties. Whether breeders are trying to improve a plant’s ability to resist disease and drought or whether they’re designing a plant to showcase bright and beautiful blooms, annuals are always being tweaked. Plant trials are the plant industry’s way of measuring how well a new variety performs. The best plant performers end up being propagated by greenhouse growers.