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

In Ypsilanti you can determine when it's possible to plant oenothera by reviewing 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.

Since oenothera are moderately cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant oenothera in Ypsilanti 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 grow to maturity. Starting your oenothera indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ypsilanti. In the coldest months of winter you should expect an average low temperature of -10°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Ypsilanti and it changes from year to year. Half of the time in Ypsilanti you get surprised by a frost after April 15 so always be ready to cover your oenothera if you have one of those late frosts.

USDA Zone Info for Ypsilanti

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 Ypsilanti

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