One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant cosmos in Lathrop can 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.

Cosmos can survive in some cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant cosmos in Lathrop 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 really do well. You can get started a couple of weeks earlier by starting your cosmos indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Lathrop. You should expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Lathrop and it can change quite a bit from year to year. Since half of the time in Lathrop last frost occurs after February 15 be ready to cover your cosmos in the event of one of those late frosts.

USDA Zone Info for Lathrop

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 Lathrop

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