The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's a good idea to plant hardy asters by using the USDA zone info for San Diego.

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.

Since hardy asters are barely cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant hardy asters in San Diego 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 fully mature. You can get started a couple of weeks earlier by starting your hardy asters indoors.

Last Frost Date

On average the last frost is on January 31 in San Diego. In the coldest months of winter you should expect an average low temperature of 35°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for San Diego and it is different every year. Half of the time in San Diego you get surprised by a frost after January 31 so make sure that you are ready to protect your hardy asters if you have a surprise late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Diego

You may be interested in your other planting guides for San Diego.