One of the first steps you take when you are estimating 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.

A common way of getting a good idea when you can plant petunias is to look at the USDA zone info for Glendora.

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 more sensitive plants.

The earliest that you can plant petunias in Glendora 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 couple of weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Glendora. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Glendora may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Glendora you get a frost after January 31 so make sure that you are ready to protect your petunias in the event of a surprise late frost.

USDA Zone Info for Glendora

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 Low	30°F
Highest Expected Low	35°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 Glendora

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