The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when to plant potatos in Zone 4b by looking at the USDA zone info.

Planting Calendar for Potatos

Frost tolerance for potatos:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Potatos tend to make it in cold weather which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant potatos in Zone 4b is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant potatos and expect a good harvest is probably August. Any later than that and your potatos may not have a chance to fully mature. Starting your potatos indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Zone 4b. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 4b and it will vary from year to year. Since half of the time in Zone 4b last frost occurs after May 15 be ready to cover your potatos in the event of a surprise late frost.

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 your other planting guides for Zone 4b.