One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 Zone 4a can be used to estimate when it's the best time to plant kale.

Planting Calendar for Kale

Frost tolerance for kale:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Kale are moderately cold tolerant which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant kale in Zone 4a 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 kale and expect a good harvest is probably August. You probably don't want to wait any later than that or else your kale may not have a chance to really do well. You can get started a couple of weeks earlier by starting your kale indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. In the coldest months of winter you should expect an average low temperature of -30°F.

It's important to remember that USDA zone info for Zone 4a is just an average and the actual date of last frost will vary from year to year. Since half of the time in Zone 4a there is a last frost after May 15 be ready to protect your kale if you have one of those late frosts.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.