One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's a good idea to plant oenothera is to use the USDA zone info for Laramie.

Planting Calendar for Oenothera

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

Oenothera are moderately cold tolerant which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant oenothera in Laramie 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. If you wait 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

On average the last frost has passed is on May 15 in Laramie. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Laramie is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Laramie it frosts late in the year after May 15 be ready to cover your oenothera in the event of a late frost.

USDA Zone Info for Laramie

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 Laramie

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