The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when you can plant oenothera is to consult the USDA zone info for Richfield.

Planting Calendar for Oenothera

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

You can plant oenothera a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant oenothera in Richfield 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 really do well. You can get started a few weeks earlier by starting your oenothera indoors.

Last Frost Date

In Richfield the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Richfield is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Richfield last frost occurs after April 15 so be sure to be ready to protect your oenothera if you have one of those late frosts.

USDA Zone Info for Richfield

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Richfield

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