When can I plant String beans in Zone 4b

One of the best tools that we have as gardeners to help us determine our 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 our area.

The first opportunity to plant string beans in Zone 4b can be figured out by using the USDA zone info.


Planting Calendar for String beans

Frost tolerance for string beans: Not tolerant of frost.
When you should plant them: After all chance of frost has passed.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant string beans
Possibly ok, but a risky time to plant string beans
Probably not a good time to plant string beans

The earliest that you can plant string beans 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 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 grow to maturity. You can get started a couple of weeks earlier by starting your string beans indoors.

Last Frost Date

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

Keep in mind that our actual date of last frost is an average because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Half of the time in Zone 4b we get surprised by a frost after May 15 so make sure that you are prepared to protect your string beans 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 our other planting guides for Zone 4b.