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 referring to the USDA zone info for Billings it's a good idea to figure out when you can plant zucchini.

Planting Calendar for Zucchini

Frost tolerance for zucchini:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant zucchini until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant zucchini in Billings 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. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

In Billings the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Keep in mind 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 Billings and it will vary from year to year. Since half of the time in Billings there is a last frost after May 15 be ready to protect your zucchini in the event of one of those late frosts.

USDA Zone Info for Billings

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 Billings

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