After getting requests from three different customers for information on plants that will grow in zones 10-11, I decided that it was time to write an article on the subject. I am by no means an expert. I've never lived in a sub-tropical climate. I'm not even sure what qualifies as sub-tropical. But I am familiar with the seeds that I sell since I've grown all of them at one time or another. So I did some research and came up with a list of plants for the warmest zones.
I found it interesting that people who live in the warmest zones regret not being able to grow plants that are only adapted to colder regions. I never thought about it before, but I realized that there is no place that is suitable for all plants. Those of us who live in colder zones bemoan our lack of tropical plants, but do we consider how we would miss our northern plants if we lived in the tropics? What about the beautiful leaf colors created by fall frosts?
I also learned some things about the state of Florida that I never knew before, even though my brother's family lived in Florida for several years (but they aren't gardeners). I discovered that there are several different hardiness zones in Florida, but experts disagree on where to draw the lines. Here's a site where you can see the various zones: Florida Hardiness Zone Maps.
When gardeners from climates that are vastly different from my own ask for advice, I refer them to Dave's Garden. That's where I get most of my hardiness zone information. The plants in the lists below should be appropriate for zone 10 (and zone 11 in some cases), as well as cooler zones. Some of the plants that we grow in the north as annuals are native to warmer regions where they are grown as perennials. These annuals are often referred to as tender perennials.
Of course, just because a plant is hardy in your area doesn't mean that it will grow well. Other conditions that affect plant growth are the amount of rainfall, the texture and quality of the soil, and the humidity. For example, zinnias grow well in the arid southwest, but they might be prone to mildew in humid climates. Annual flowers like sweet peas that prefer cooler weather are only grown during the "winter" months in Florida. It's worth taking the time to do some research before trying new plants.
Hardy Perennials for the Warmest Zones
Tender Perennials
Annuals