When to Plant Asters in Fontana, 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.

You can estimate when it's a good idea to plant asters in Fontana by reviewing 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 are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

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 Fontana 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. If you are starting your asters indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Fontana the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Fontana and it is different every year. Half of the time in Fontana last frost occurs after January 31 so make sure that you are prepared to cover your asters in the event of a surprise late frost.

USDA Zone Info for Fontana

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 Fontana

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