When can I plant Hardy Asters in Zone 9a

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

In Zone 9a you can determine when it's possible to plant hardy asters by reviewing the USDA zone info.


Planting Calendar for Hardy Asters

Frost tolerance for hardy asters: Tolerant of a very small amount of frost.
When you should plant them: Up to 3 weeks before last frost.

Since hardy asters are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive 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 Zone 9a 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. Starting your hardy asters indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zone 9a the average date of last frost happens on February 15. We should expect an average low temperature of 20°F in the coldest months of winter.

Always keep in mind that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 9a and it is different every year. Since half of the time in Zone 9a we get surprised by a frost after February 15 be ready to protect your hardy asters if we have one of those late frosts.

USDA Zone Info for Zone 9a

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 Zone 9a

You may be interested in our other planting guides for Zone 9a.