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.

You can determine when it's the best time to plant asters in Cotati by using the USDA zone info.

Planting Calendar for Asters

Frost tolerance for asters:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Asters are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant asters in Cotati is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant asters and expect a good harvest is probably October. Any later than that and your asters may not have a chance to fully mature. Starting your asters indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Cotati. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Cotati may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Cotati you get surprised by a frost after February 15 so make sure that you are ready to protect your asters if you have one of those late frosts.

USDA Zone Info for Cotati

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 Cotati

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