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.

By reviewing the USDA zone info for Woodland Park you should be able to determine when it's a good idea to plant oenothera.

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 just a bit earlier in the year than more sensitive plants.

The earliest that you can plant oenothera in Woodland Park 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. You probably don't want to wait any later than that or else 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

On average the last frost when the weather gets warmer is on April 15 in Woodland Park. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Woodland Park is an average the actual date of last frost changes from year to year. Half of the time in Woodland Park you get surprised by a frost after April 15 so just be sure to be ready to cover your oenothera in the event of a late frost.

USDA Zone Info for Woodland Park

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Woodland Park

You may be interested in your other planting guides for Woodland Park.