Does anyone else here grow coreopsis and finding it grows way over the expected size? I love it being tall but it's always unexpected.

Years I bought some that has the tiny yellow and burgundy color flowers. The first year it grew only a few inches and didn't flower. I was disappointed. The next year though it grew 6.5 feet. I have since found that they want to act like bi-annuals.

This year I got a pack of assorted seeds for a new flower bed. Almost nothing grew from that pack. I did have 2 plants slowly start to come up in the back. It took all summer to get a few feet high before they started to explode in height. I could tell they were a version of coreopsis. This one was an all yellow variety and it has a much thicker trunk. Well once it started blooming last month it was 7.5 ft high. Unfortunately there were only 2 and the heavy rains this week snapped one off at the base. The other is laying on the air-conditioning unit.

Usually I find plants grow close to what the package says but coreopsis always goes way over what the listings show.