One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A common way of making a decision about when you can plant petunias is to consult the USDA zone info for Gardena.

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 barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant petunias in Gardena 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. If you wait any later than that and your petunias may not have a chance to fully mature. If you are starting your petunias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Gardena the average date of last frost happens on January 31. It might get as low as 35°F during the coldest months of winter.

Since the USDA zone info for Gardena is not always accurate the actual date of last frost changes from year to year. Half of the time in Gardena you get a frost after January 31 so just be sure to be ready to cover your petunias in the event of a late frost.

USDA Zone Info for Gardena

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Gardena

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