When can I plant Cosmos in Zone 11b

Before planting it is a good idea to find our USDA Zone info to estimate our garden 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 estimate when it's possible to plant cosmos in Zone 11b by checking out 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.

Cosmos do well in very little cold which means that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

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 11b 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your cosmos indoors.

Last Frost Date

In Zone 11b it never frosts. We should expect an average low temperature of 45°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 11b is an average and our actual date of last frost changes from year to year. Since it never frosts in Zone 11b you do not have to be ready to cover your cosmos if we have a surprise late frost.

USDA Zone Info for Zone 11b

Here is the info for USDA Zone 11b.

Average Date of Last Frost (spring)Never
Average Date of First Frost (fall)Never
Lowest Expected Low45°F
Highest Expected Low50°F

This means that on a really cold year, the coldest it will get is 45°F. On most years you should be prepared to experience lows near 50°F.

Plants to Grow in Zone 11b

You may be interested in our other planting guides for Zone 11b.