One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant cosmos is to refer to the USDA zone info for Hayward.

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 do well in a tiny bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant cosmos in Hayward 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 when the weather gets warmer is on January 31 in Hayward. You can expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that USDA zone info for Hayward is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Hayward there is a last frost after January 31 be ready to protect your cosmos in the event of a late frost.

USDA Zone Info for Hayward

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 Hayward

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