One of the first steps you take when you are determining 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.

The USDA zone info for Thornton should be looked at to figure out when it's possible to plant string beans.

Planting Calendar for String beans

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

Since string beans require warm weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant string beans 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 string beans and expect a good harvest is probably August. You probably don't want to wait any later than that or else your string beans may not have a chance to fully mature. Starting your string beans indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Thornton is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Thornton last frost occurs after April 15 so make sure that you are prepared to protect your string beans in the event of a late frost.

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.