The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for San Luis can be used to figure out when it's the best time 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.

You can plant cosmos just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant cosmos in San Luis 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. Any later than that and your cosmos may not have a chance to fully mature. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In San Luis the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that USDA zone info for San Luis may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in San Luis it frosts late in the year after January 31 be ready to protect your cosmos if you have a late frost.

USDA Zone Info for San Luis

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 San Luis

You may be interested in your other planting guides for San Luis.