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

You can figure out when you can plant datura in Ottumwa by using 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 one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant datura in Ottumwa 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 grow to maturity. If you are starting your datura indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Ottumwa is just an average and the actual date of last frost changes from year to year. Half of the time in Ottumwa it frosts late in the year after April 15 so be sure to be ready to cover your datura in the event of one of those late frosts.

USDA Zone Info for Ottumwa

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 Ottumwa

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