When can I plant Cosmos in Zone 12a

The USDA Zone info is a great tool for gardeners to help us determine our gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

You can determine when you can plant cosmos in Zone 12a by using the USDA zone info.


Planting Calendar for Cosmos

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

Since cosmos do ok in moderate cold you can plant them just a tiny bit earlier in the year than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant cosmos
Possibly ok, but a risky time to plant cosmos
Probably not a good time to plant cosmos

The earliest that you can plant cosmos in Zone 12a 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. If you wait 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 12a it never frosts. In the coldest months of winter we can expect an average low temperature of 50°F.

Since the USDA zone info for Zone 12a is not always accurate our actual date of last frost is different every year. Since it never frosts in Zone 12a you do not have to be ready to cover your cosmos if we have a late frost.

USDA Zone Info for Zone 12a

Here is the info for USDA Zone 12a.

Average Date of Last Frost (spring)Never
Average Date of First Frost (fall)Never
Lowest Expected Low50°F
Highest Expected Low55°F

This means that on a really cold year, the coldest it will get is 50°F. On most years you should be prepared to experience lows near 55°F.

Plants to Grow in Zone 12a

You may be interested in our other planting guides for Zone 12a.