The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Corona you can estimate when it's the best time to plant dahlias by reviewing the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant dahlias until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias in Corona 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. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Corona. You can expect an average low temperature of 25°F in the coldest months of winter.

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 Corona and it can change quite a bit from year to year. Half of the time in Corona last frost occurs after February 15 so make sure that you are prepared to cover your dahlias in the event of one of those late frosts.

USDA Zone Info for Corona

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 Low	25°F
Highest Expected Low	30°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 Corona

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