One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Naperville you can determine when to plant runner beans by referring to the USDA zone info.

Planting Calendar for Runner beans

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

Runner beans require warm weather which means that you really should wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

The average date of last frost is April 15 in Naperville. It might get as low as -15°F during the coldest months of winter.

Just be sure 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 Naperville and it will vary from year to year. Half of the time in Naperville last frost occurs after April 15 so just be sure to be ready to protect your runner beans if you have a late frost.

USDA Zone Info for Naperville

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 Naperville

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