When to Plant Cosmos in Belmont, CA

One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Belmont you can determine when it's a good idea to plant cosmos by reviewing 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.

Cosmos are one of those plants that can tolerate a tiny bit of cold weather which means that you can start planting them slightly earlier 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 Belmont 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. You probably don't want to wait any later than that or else your cosmos may not have a chance to really do well. If you are starting your cosmos indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in Belmont. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Belmont is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Belmont it frosts late in the year after January 31 so just be sure to be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Belmont

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 Belmont

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