When to Plant Cosmos in Arcadia, CA

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

In Arcadia you can figure out when to plant cosmos 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.

You can plant cosmos slightly earlier in the year because they are barely cold tolerant.

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 Arcadia is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant cosmos and expect a good harvest is probably September. If you wait any later than that and your cosmos may not have a chance to fully mature. You can get started a few weeks earlier by starting your cosmos indoors.

Last Frost Date

The average date of last frost is January 31 in Arcadia. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Arcadia and it can change quite a bit from year to year. Half of the time in Arcadia there is a last frost after January 31 so make sure that you are prepared to cover your cosmos in the event of a surprise late frost.

USDA Zone Info for Arcadia

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)January 31
Average Date of First Frost (fall)December 15
Lowest Expected Low30°F
Highest Expected Low35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Arcadia

You may be interested in your other planting guides for Arcadia.