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.

In California you can figure out when to plant hardy asters by referring to the USDA zone info.

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.

Hardy Asters are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant hardy asters in California is March. However, you really should wait until April 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 August. Any later than that and your hardy asters may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your hardy asters indoors.

Last Frost Date

In California the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

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

USDA Zone Info for California

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in California

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