Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Astoria can be used to estimate when you can plant petunias.

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 one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant petunias in Astoria 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. If you wait any later than that and your petunias may not have a chance to really do well. You can get started a couple of weeks earlier by starting your petunias indoors.

Last Frost Date

The average date of last frost is March 15 in Astoria. In the coldest months of winter you can expect an average low temperature of 15°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Astoria and it will vary from year to year. Half of the time in Astoria you get a frost after March 15 so be sure to be ready to cover your petunias in the event of one of those late frosts.

USDA Zone Info for Astoria

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Astoria

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