One of the best tools that you have as gardeners to help us estimate 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.

In Louisville you can figure out when it's the best time to plant oenothera by referring to the USDA zone info.

Planting Calendar for Oenothera

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

Oenothera do well in some cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

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

Last Frost Date

The average date of last frost is April 15 in Louisville. It might get as low as 0°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Louisville and it is different every year. Since half of the time in Louisville you get a frost after April 15 be ready to cover your oenothera in the event of a late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Louisville

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