I'm going to research this, but it sounds like a ridiculous claim. The Chicago Botanical Garden didn't make this claim, did they?

Ok, so all Zinnia are annuals. They won't overwinter, or even return in a tropical climate. You have to start new plants every year. Are you sure you weren't reading about the perennial Zizia?

I've never heard of a zinnia being a perennial in colder zones.

Hardiness does not pertain to whether a plant is an annual or a perennial. The hardiness of plants describes their ability to survive adverse growing conditions. And the most usual adverse growing condition is cold weather. Hence the hardiness zones, which identify the average worst cold weather conditions. For more details, see this link to Wikipedia.

ZM

Jay

No, it was labeled zinnia. Just not the var. It was also not not labeled annual or perrenial. So I googled it to find the var, which I determined as Angustifolia based on the pic above that looks just like it, & then goigled to see whether annual or perennial, as I thought most zinnias were annuals but you never know these days w/ hybridizing. Entries for this plant listed it as hardy to zone 2 but also as an annual, thats where the confusion came from. I always thought if it returned after winter or below frezing temps, then it was considered a perennial, and zone 2 is Alaska so I thought “if it would survive an Alaskan winter, why is it labelled as an annual?” .

zen_man, thank you for clearing that up about hardiness..

A true annual is an annual anywhere on the planet. They should not have hardiness zones at all.

I appreciate an indication of where re-seeding occurs without the need to save seeds inside, or concern about having too many seedlings the following year, but that's not hardiness. That's just where re-seeding occurs.

Hardiness has nothing to do with adverse growing conditions, just where a plant can and can't survive perennially. Some plants from cold native habitats can't survive where winters are too warm or non-existent, like lilac (Syringa vulgaris.) And many tropical plants can't survive where winters are too cold. Everyone is familiar with many of these "as annuals" or houseplants.

If you like it plant it and save some seeds. Or leave it alone in the garden. While there are no guarantees you could get volunteers. I get them routinely in mulched beds. Doesn't make them perennial but it just reminds me that mother nature rules. Buy what you love because life is way too short to deprive yourself of beauty today.