In Animal Crossing: New Horizons, it's now possible to buy bushes that only flower at different times of the year. You can buy these bushes from Leaf who will be on the town hall square from time to time. They can be planted almost everywhere on your island, but you must nevertheless avoid putting them too close to the cliffs, infrastructures and paths that you could have created with terraforming.
The list of available bushes and their flowerings
At the moment, we don't know if hybridization between the bushes is possible to obtain other colors.
Images from the gamewith site.