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When to Plant Petunias in Rohnert Park, CA

One of the first steps you take when you are determining 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 using the USDA zone info for Rohnert Park it's a good idea to estimate when it's the best time to plant petunias.


Planting Calendar for Petunias

Frost tolerance for petunias: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since petunias 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 petunias
Possibly ok, but a risky time to plant petunias
Probably not a good time to plant petunias

The earliest that you can plant petunias in Rohnert Park 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 petunias and expect a good harvest is probably September. You probably don't want to wait any later than that or else your petunias may not have a chance to grow to maturity. If you are starting your petunias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Rohnert Park. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Rohnert Park is not always accurate the actual date of last frost changes from year to year. Half of the time in Rohnert Park there is a last frost after February 15 so make sure that you are ready to cover your petunias if you have a surprise late frost.

USDA Zone Info for Rohnert Park

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low25°F
Highest Expected Low30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rohnert Park

You may be interested in your other planting guides for Rohnert Park.