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.

The first chance to plant oenothera in Wilmette can be estimated by using 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 ok in moderate cold which means that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant oenothera in Wilmette 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. 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

On average the last frost when the weather gets warmer is on April 15 in Wilmette. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Wilmette is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Wilmette last frost occurs after April 15 so just be sure to be ready to protect your oenothera in the event of one of those late frosts.

USDA Zone Info for Wilmette

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 Wilmette

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