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.

By referring to the USDA zone info for Winterset you will be able to estimate when it's possible to plant oenothera.

Planting Calendar for Oenothera

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

Since oenothera do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant oenothera in Winterset is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant oenothera and expect a good harvest is probably September. Any later than that and your oenothera may not have a chance to fully mature. Starting your oenothera indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Winterset the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Winterset is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Winterset last frost occurs after April 15 be ready to cover your oenothera in the event of a surprise late frost.

USDA Zone Info for Winterset

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Winterset

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