You need to do research to find what is best in your area. Most growers will list plants as early, mid, or late. You can use that as a basis but the sequence is based on the bloom time of Red Charm and not a actual date. The last couple of years my plants have been all mixed up as to bloom time.

The species generally bloom early. My first used to be the first week in March but has moved to the second week. Then some of the singles, then starts the rest and end up with the full doubles. The full doubles will need support for their bloom stems but even with the support I would suggest that you cut a few before they are fully open. Leave outside overnight with the stems in water so the ants will leave.

It may just be one of those things but when the doubles break into full bloom heavy rains will happen. If you cut and take some in they can last a while in a container.