The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to determine when it's the best time to plant oenothera by using the USDA zone info for Oskaloosa.

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 get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant oenothera in Oskaloosa 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. 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 little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Oskaloosa. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Oskaloosa is an average and the actual date of last frost changes from year to year. Half of the time in Oskaloosa 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 surprise late frost.

USDA Zone Info for Oskaloosa

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Oskaloosa

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