It's funny how, once a topic crops up, it often reoccurs. My most recent example was in discussing tags with customers. My advice is, "Don't believe everything you read on a tag." Overall, they can be helpful, but they are written in general terms. It may say perennial, but when you read closely, it's only perennial to zone 7 ( we're zone 6.) Some perennial tags say "blooms all summer." Perennials have a season of bloom and a month is a long bloom time for perennials. It's actually annuals that boom all summer, in many cases.
A customer complimented us on the hydrangeas blooming in front of our house. She asked what I did to produce such a result. I replied, "Absolutely nothing!" A combination of the mild winter and wet spring produced a floriferous display.
Now that we're into summer, I'm harvesting regularly from the gardens. It's still mostly perennial culinary herbs like mints, tarragon, savory, sage, oregano, etc. at this point. I'm also picking flowers to dry as they bloom. Beautiful yellow yarrow is very productive and dries well.