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

By looking at the USDA zone info for Portland it's a good idea to figure out when it's possible to plant datura.

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.

You can plant datura a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant datura in Portland 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 really do well. You can get started a few weeks earlier by starting your datura indoors.

Last Frost Date

The average date of last frost is April 15 in Portland. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Portland and it can change quite a bit from year to year. Since half of the time in Portland you get a frost after April 15 be ready to cover your datura in the event of a surprise late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 5b.

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

Plants to Grow in Portland

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