The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when to plant oenothera in Stewartville by looking at the USDA zone info.

Planting Calendar for Oenothera

Frost tolerance for oenothera:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Oenothera do ok in mild cold which means that you can plant them a little earlier in the year than other frost tender plants.

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

Last Frost Date

On average the last frost has passed is on May 15 in Stewartville. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that USDA zone info for Stewartville is just an average and the actual date of last frost is different every year. Since half of the time in Stewartville you get a frost after May 15 be ready to protect your oenothera in the event of a surprise late frost.

USDA Zone Info for Stewartville

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Stewartville

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