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.

One way of estimating when it's a good idea to plant hardy asters is to consult the USDA zone info for Azusa.

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 barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant hardy asters in Azusa 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. Any later than that and your hardy asters may not have a chance to really do well. You can get started a little bit earlier by starting your hardy asters indoors.

Last Frost Date

The average date of last frost is January 31 in Azusa. It might get as low as 30°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Azusa and it will vary from year to year. Half of the time in Azusa you get surprised by a frost after January 31 so make sure that you are ready to protect your hardy asters in the event of one of those late frosts.

USDA Zone Info for Azusa

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Azusa

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