I recently learned that our plant database does not incorporate hardiness zones on annual flowers. I mean it makes sense since annuals die in the winter/frost. With that being said it can be a bit confusing when I go to seed websites and they all show hardiness zones on their annual packages. For example, I want to purchase Mexican zinnia seeds. They are annual flowers. The websites say zones 11 and 12 which doesn't make me too happy since I am in zone 10a here in west-central Florida. This kind of got me thinking though. If annuals technically shouldn't have hardiness zones, should I even worry about the hardiness zones websites say for annuals? I feel like I should just ignore the hardiness zones. I would think zone 10a would be paradise anyway for any plant to grow and flourish.

Let me know your thoughts

One site I looked at mentioned that the Mexican zinnias "thrive in zones 11 and 12" — I think that is just to indicate that the plants can withstand extremely high heat, not that they are limited to those zones. You are correct, cold hardiness is not an issue with summer annuals. There are some that do have upper temperature limits...nothing that comes to mind at the moment, but I've seen comments in this forum saying that putting upper temp zones in the database is misleading and not always accurate (I have seen upper zones listed for some plants). I can see the problem with that, because ambient temps can sometimes be manipulated by placement in shady areas or near water, but some plants definitely need a cooler range than others.

Sorry, I digressed. Yes, ignore zone designations. I'd think you can grow just about any summer annual in your paradise zone.

There are true annuals, and then there are plants that are perennials but can't survive perennially in some locations and when sold in those locations, are called annuals to prevent unrealistic expectations. A true annual can't survive perennially in any location. Not all true annuals are summer entities.

Looking at zones for an annual plant is a great way to figure out the lowest temperatures a plant can withstand.

A true annual shouldn't have any zones attached to it.

purpleinopp said:There are true annuals, and then there are plants that can't survive perennially in some locations and when sold in those locations, are called annuals to prevent unrealistic expectations. A true annual can't survive perennially in any location. Not all true annuals are summer entities.

Agree completely. That's why I specified "summer annuals," because that's what OP asked about. I'd already digressed once and actually deleted my commentary on perennials grown as annuals because it got too wordy plus, there won't be too many exceptions for warm weather in zone 10.

Awww, I bet your commentary was great! Most of the plants sold as annuals in temperate areas are perennials that can't take freezing temps.

There are annuals that, in a warm climate, are only around during the colder months. At this time where I am, there is chickweed, velcro-weed (Galium), "wild mustard" that disappear just when it seems like they are going to take over the world. Soon there will be several types of "clover" putting on a great show, that will perish when the heat comes. Aren't most types of lettuce in this category? When I lived in OH, these were summer entities, except for the Galium which I never noticed there, if it was present. It seems like more of a matter of timing than zone.

Hey guys. Thank you so much for all the replies! I must have missed the notification bell somehow on this thread. I appreciate all the information on annuals. I would freak out when I would order seeds and then on the back of the packages, when the seeds arrive, it would give a hardiness zone between 3-8. I guess I can finally lay those thoughts to rest.

It's definitely warm down here for really any annual to grow I would think. I'm a big perennial grower but am really trying to order more annuals. They are usually insanely gorgeous. Now that we are in February, I think it's safe to start planting seeds. January is literally the only month I don't care to plant seeds here. We just got done with that northeastern weather pattern. The lowest we got in my city was I believe 33 or 34F°, but there were parts of the Tampa Bay area here that got into the 20s.

Petabread ~ in Florida you can grow things at different times of the year than most of the country. I was reading a book on Kindle called Cool Flowers. I should have started snapdragons in September. Pansies and Violas as well. Still, it is still winter, so snaps and violas next year. They take a long time to germinate and become established.

I already sowed some sweet peas though. We are due for more than one snowstorm, as winter isn't over yet, though lately we have had spring-like weather. Not really warm though, about 55° at the highest, with a cold breeze. I have to bundle up to work outside.

Are you getting the cold weather that some Floridians are getting now...some even in the 20's.

evelyninthegarden said:
Are you getting the cold weather that some Floridians are getting now...some even in the 20's.

Oh no, that was really only one night in the greater region I live in, Tampa Bay. The city I live in got down to 33 one night. That's cold front past now. If temps get that low it usually only happens one time in a year.

In short Petabread, when they mention zones on the tags on something that is being sold as an annual, it only means it is perennial in those zones mentioned. The rest of us can grow it as an annual, not that we can't or shouldn't grow it. Anyway, like Evelyn said, your season for annuals run differently than for the rest of us further north. I remember my cousin, who lived in Boca Raton at the time, planted her annual transplants, like impatiens, in the fall.

Evelyn, this post made me think of the same thing. I also read the book by Lisa Ziegler on Cool Flowers. I really liked the concept and how she rates the winter hardiness of annuals to make it as seedlings through the winter if started 8 weeks prior to the first frost. If I knew we were going to have such a long fall, I could have done it this year.

Loretta ~ Theoretically, I knew to start some seeds earlier, but wasn't quite ready at the time. Reading Cool Flowers reminded me. I really love snapdragons and pansies, but of course there are more, too. I will remind myself to re-read it in August, so I can get everything ready. And make a space in the basement (again!) for seed-starting! Hubby quickly absconded with the space when I had a broken ankle, then hip replacement. I was out of the garden and even walking for a while.

We have winter annuals, like pansies and Iceland poppies, and summer annuals like marigolds and petunias. It gets too hot for the poppies in the summer and too cold for the marigolds in the winter. Primroses melt in June and zinnias really look like crap in December. Like so many things it's all about location, location, location.

CPPgardener said:We have winter annuals, like pansies and Iceland poppies, and summer annuals like marigolds and petunias. It gets too hot for the poppies in the summer and too cold for the marigolds in the winter. Primroses melt in June and zinnias really look like crap in December. Like so many things it's all about location, location, location.

...and timing.

Petabread ~ There are many reasons that annuals may not be designated into zones. However, if you are wanting to get the most out of your favorite annuals, it is important to know when to sow them and, yes, how hardy are they?

There are 2 basic categories of annuals. Hardy annuals, and tender annuals. And some perennials can be grown as annuals, if you don't have the right climate to grow them as perennials, such as delphiniums, as they flop during hot summers, but love cool and cold weather.

A very informative book on this very subject is Cool Flowers by Lisa Mason Ziegler

Here is a link: https://www.amazon.com/dp/B07JBY9YS9/

I may have mentioned this previously, but I forgot to add a link.

evelyninthegarden said: …some perennials can be grown as annuals….

Most of the perennials I grow become annuals. It is a special talent I have.

It is winter and I have started some seeds outside on the back porch.

The first one that are already up are calendulas that were sown on the 8th of February.


The rest were sown later including today.

No fancy propagation kits. Just recycled and cleaned cell-packs and produce bags to cover until germination.

Wow @evelyninthegarden - Great work!
I see a very large yard space down below. Is that all yours to garden with? I would be in love if I had all that land!

Petabread said: I see a very large yard space down below. Is that all yours to garden with? I would be in love if I had all that land!

Deer-infested hard clay soil. Plus I am 80 years old and I have a hard time keeping up with the gardens that I have already started. If you want to come and help, you are certainly welcome!