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.

You can figure out when it's possible to plant cosmos in Rocklin by using 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 do ok in very little cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Rocklin 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 little bit earlier by starting your cosmos indoors.

Last Frost Date

In Rocklin the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

It's important to remember that USDA zone info for Rocklin is not always accurate and the actual date of last frost is different every year. Half of the time in Rocklin there is a last frost after February 15 so be sure to be ready to cover your cosmos if you have a surprise late frost.

USDA Zone Info for Rocklin

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rocklin

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