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.

By using the USDA zone info for Suisun City you will be able to figure out when you can plant hardy asters.

Planting Calendar for Hardy Asters

Frost tolerance for hardy asters:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant hardy asters just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant hardy asters in Suisun City 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 hardy asters and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy asters may not have a chance to grow to maturity. You can get started a little bit earlier by starting your hardy asters indoors.

Last Frost Date

In Suisun City the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Suisun City and it will vary from year to year. Since half of the time in Suisun City you get a frost after February 15 be ready to cover your hardy asters if you have a surprise late frost.

USDA Zone Info for Suisun City

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 Suisun City

You may be interested in your other planting guides for Suisun City.