The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Umatilla you can figure out when it's a good idea to plant datura by referring to the USDA zone info.

Planting Calendar for Datura

Frost tolerance for datura:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Datura are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant datura 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 datura and expect a good harvest is probably August. Any later than that and your datura may not have a chance to fully mature. You can get started a few weeks earlier by starting your datura indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Umatilla. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Umatilla is an average the actual date of last frost changes from year to year. Since half of the time in Umatilla you get surprised by a frost after April 15 be ready to protect your datura in the event of a surprise late frost.

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.