One of the first steps you take when you are figuring out 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 common way of determining when you can plant zucchini is to look at the USDA zone info for Thornton.

Planting Calendar for Zucchini

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

Zucchini require warm weather which tells us that it is necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant zucchini in Thornton 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. Any later than that and your zucchini may not have a chance to really do well. You can get started a few weeks earlier by starting your zucchini indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Thornton. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Thornton is just an average and the actual date of last frost changes from year to year. Half of the time in Thornton there is a last frost after April 15 so always be ready to protect your zucchini if you have one of those late frosts.

USDA Zone Info for Thornton

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 Thornton

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