When to Plant Asters in Union City, CA

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's a good idea to plant asters in Union City by checking out the USDA zone info.


Planting Calendar for Asters

Frost tolerance for asters: Tolerant of some frost.
When to plant: Up to 5 weeks before last frost.

Since asters do well in moderate cold you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant asters in Union City is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant asters and expect a good harvest is probably October. You probably don't want to wait any later than that or else your asters may not have a chance to fully mature. Starting your asters indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Union City. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Union City may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Union City you get surprised by a frost after January 31 so just be sure to be ready to protect your asters in the event of a surprise late frost.

USDA Zone Info for Union City

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 Union City

You may be interested in your other planting guides for Union City.