The following Google Doc is an ongoing, ever evolving list of plants that work well in Denver’s Climate. Included are water and sun requirements, native vs non native, bloom time, and wildlife benefit. When possible, I recommend choosing native plants.
https://docs.google.com/spreadsheets/d/1f9NvTjKY8osy-fJwfXpvMnjO0Y08rNRJmkfAHTVdV0A/edit?usp=sharing