One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when to plant datura by looking at the USDA zone info for Denver.

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 just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant datura in Denver 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. If you wait any later than that and your datura may not have a chance to really do well. You can get started a little bit earlier by starting your datura indoors.

Last Frost Date

The average date of last frost is April 15 in Denver. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Denver and it will vary from year to year. Since half of the time in Denver you get surprised by a frost after April 15 be ready to protect your datura in the event of one of those late frosts.

USDA Zone Info for Denver

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 Denver

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