One of the first steps you take when you are making a decision about 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.

The USDA zone info for Marengo can be reffered to in order to estimate when it's the best time 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.

Since datura do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant datura in Marengo 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 couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Marengo. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Marengo is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Marengo you get surprised by a frost after April 15 so just be sure to be ready to cover your datura in the event of a late frost.

USDA Zone Info for Marengo

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 Marengo

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