The USDA Zone info is a great tool for gardeners to help us determine 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.

You will be able to figure out when it's the best time to plant oenothera by using the USDA zone info for Galesburg.

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

The earliest that you can plant oenothera in Galesburg 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. Any later than that and your oenothera may not have a chance to grow to maturity. If you are starting your oenothera indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Galesburg. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Galesburg is an average the actual date of last frost will vary from year to year. Since half of the time in Galesburg it frosts late in the year after April 15 be ready to protect your oenothera if you have a late frost.

USDA Zone Info for Galesburg

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 Galesburg

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