Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant cosmos in Zone 12b should be estimated by looking at the USDA zone info.

Planting Calendar for Cosmos

Frost tolerance for cosmos:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since cosmos are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Zone 12b is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant cosmos and expect a good harvest is probably November. Any later than that and your cosmos may not have a chance to grow to maturity. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Zone 12b it never frosts. In the coldest months of winter you should expect an average low temperature of 55°F.

Since the USDA zone info for Zone 12b may not be accurate from year to year the actual date of last frost is different every year. Since it never frosts in Zone 12b you do not have to be ready to protect your cosmos in the event of a late frost.

USDA Zone Info for Zone 12b

Here is the info for USDA Zone 12b.

Average Date of Last Frost (spring)	Never
Average Date of First Frost (fall)	Never
Lowest Expected Low	55°F
Highest Expected Low	60°F

This means that on a really cold year, the coldest it will get is 55°F. On most years you should be prepared to experience lows near 60°F.

Plants to Grow in Zone 12b

You may be interested in your other planting guides for Zone 12b.