Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 possible to plant hardy asters in Mill Valley by using 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 do ok in moderate cold which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant hardy asters in Mill Valley 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 few weeks earlier by starting your hardy asters indoors.

Last Frost Date

On average all chance of frost has passed is on January 31 in Mill Valley. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Mill Valley is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Mill Valley you get a frost after January 31 be ready to cover your hardy asters in the event of a late frost.

USDA Zone Info for Mill Valley

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 Mill Valley

You may be interested in your other planting guides for Mill Valley.