The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Zone 4b you will be able to determine when you can plant zucchini.

Planting Calendar for Zucchini

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

You really shouldn't plant zucchini until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant zucchini in Zone 4b is May. However, you really should wait until June 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. Any later than that and your zucchini may not have a chance to really do well. If you are starting your zucchini indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. You should expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Zone 4b and it will vary from year to year. Half of the time in Zone 4b last frost occurs after May 15 so make sure that you are prepared to cover your zucchini in the event of one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.