Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Grand Forks you can determine when you can plant oenothera by using 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 are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant oenothera in Grand Forks 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. You probably don't want to wait any later than that or else your oenothera may not have a chance to really do well. Starting your oenothera indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Grand Forks. In the coldest months of winter you can expect an average low temperature of -30°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Grand Forks and it changes from year to year. Since half of the time in Grand Forks you get a frost after May 15 be ready to protect your oenothera in the event of one of those late frosts.

USDA Zone Info for Grand Forks

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Grand Forks

You may be interested in your other planting guides for Grand Forks.