When to Plant Dahlias in Hercules, CA

One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Hercules you can determine when it's the best time to plant dahlias by checking out the USDA zone info.


Planting Calendar for Dahlias

Frost tolerance for dahlias: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Since dahlias are not cold tolerant you must wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant dahlias in Hercules is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably September. Any later than that and your dahlias may not have a chance to fully mature. You can get started a little bit earlier by starting your dahlias indoors.

Last Frost Date

In Hercules the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Hercules and it changes from year to year. Half of the time in Hercules there is a last frost after February 15 so make sure that you are ready to cover your dahlias if you have a late frost.

USDA Zone Info for Hercules

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 Hercules

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