The USDA Zone info is a great tool for gardeners to help us determine 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 best time to plant cosmos in Oakland should be determined 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.

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

The earliest that you can plant cosmos in Oakland 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. Starting your cosmos indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Oakland. In the coldest months of winter you can expect an average low temperature of 30°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Oakland and it is different every year. Half of the time in Oakland it frosts late in the year 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 Oakland

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 Low	30°F
Highest Expected Low	35°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 Oakland

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