One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's a good idea to plant oenothera is to refer to the USDA zone info for Joliet.

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 one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant oenothera in Joliet 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 really do well. If you are starting your oenothera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Joliet the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Joliet may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Joliet it frosts late in the year after April 15 be ready to cover your oenothera if you have one of those late frosts.

USDA Zone Info for Joliet

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 Joliet

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