Before planting it is a good idea to find your USDA Zone info to determine 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.

By referring to the USDA zone info for Chicago it's possible to estimate when it's the best time to plant zucchini.

Planting Calendar for Zucchini

Frost tolerance for zucchini:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant zucchini until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant zucchini in Chicago is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zucchini and expect a good harvest is probably August. If you wait any later than that and your zucchini may not have a chance to grow to maturity. You can get started a little bit earlier by starting your zucchini indoors.

Last Frost Date

The average date of last frost is April 15 in Chicago. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Chicago and it changes from year to year. Half of the time in Chicago it frosts late in the year after April 15 so always be ready to cover your zucchini in the event of one of those late frosts.

USDA Zone Info for Chicago

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Chicago

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