Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant oenothera in Winona can be figured out by referring to 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 a little bit of cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant oenothera in Winona 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 fully mature. If you are starting your oenothera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Winona the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Winona is an average the actual date of last frost will vary from year to year. Half of the time in Winona you get a frost after May 15 so just be sure to be ready to protect your oenothera if you have one of those late frosts.

USDA Zone Info for Winona

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 Winona

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