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.

The USDA zone info for Iola should be read to figure out when you can plant oenothera.

Planting Calendar for Oenothera

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

You can plant oenothera just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant oenothera in Iola 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 fully mature. You can get started a couple of weeks earlier by starting your oenothera indoors.

Last Frost Date

The average date of last frost is April 15 in Iola. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Iola and it changes from year to year. Half of the time in Iola you get surprised by a frost after April 15 so make sure that you are prepared to cover your oenothera if you have one of those late frosts.

USDA Zone Info for Iola

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Iola

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