The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant petunias in Umatilla can be determined by referring to the USDA zone info.

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

The earliest that you can plant petunias in Umatilla 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. 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 little bit earlier.

Last Frost Date

In Umatilla the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Remember that USDA zone info for Umatilla may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Umatilla it frosts late in the year after April 15 so make sure that you are prepared to cover your petunias in the event of one of those late frosts.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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