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.

In Patterson you can figure out when to plant cosmos by checking out 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 a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant cosmos in Patterson 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. 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 Patterson. In the coldest months of winter you should expect an average low temperature of 20°F.

Keep in mind 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 Patterson and it changes from year to year. Half of the time in Patterson there is a last frost after February 15 so make sure that you are prepared to protect your cosmos if you have one of those late frosts.

USDA Zone Info for Patterson

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Patterson

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