When to Plant Hardy Asters in Walnut, CA

One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The first opportunity to plant hardy asters in Walnut can be determined 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 to plant: 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 plants that are more sensitive to the cold.

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 Walnut 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. If you wait any later than that and 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 has passed is on January 31 in Walnut. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Walnut is not always accurate the actual date of last frost changes from year to year. Half of the time in Walnut you get a frost after January 31 so always be ready to cover your hardy asters in the event of a late frost.

USDA Zone Info for Walnut

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 Low30°F
Highest Expected Low35°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 Walnut

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