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

One way of estimating when to plant petunias is to look at the USDA zone info for Riverdale.

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.

Petunias tend to make it in some cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant petunias in Riverdale 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 petunias and expect a good harvest is probably August. Any later than that and your petunias may not have a chance to fully mature. Starting your petunias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Riverdale the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 10°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Riverdale and it changes from year to year. Since half of the time in Riverdale last frost occurs after March 15 be ready to protect your petunias in the event of a surprise late frost.

USDA Zone Info for Riverdale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Riverdale

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