The USDA Zone info is a great tool for gardeners to help us figure out 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.

The USDA zone info for Pleasanton should be reviewed to estimate when to plant cosmos.

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 barely cold tolerant which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant cosmos in Pleasanton 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 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

The average date of last frost is February 15 in Pleasanton. You should expect an average low temperature of 20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Pleasanton and it is different every year. Since half of the time in Pleasanton there is a last frost after February 15 be ready to protect your cosmos in the event of one of those late frosts.

USDA Zone Info for Pleasanton

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Pleasanton

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