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When to Plant Hardy Asters in Calistoga, CA

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Calistoga it's a good idea to figure out when it's a good idea to 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.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hardy asters
Possibly ok, but a risky time to plant hardy asters
Probably not a good time to plant hardy asters

The earliest that you can plant hardy asters in Calistoga 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 really do well. If you are starting your hardy asters indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Calistoga. In the coldest months of winter you can expect an average low temperature of 20°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Calistoga and it can change quite a bit from year to year. Half of the time in Calistoga there is a last frost after February 15 so make sure that you are ready to protect your hardy asters in the event of a late frost.

USDA Zone Info for Calistoga

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low20°F
Highest Expected Low25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Calistoga

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