One of the best tools that you have as gardeners to help us determine 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 Zone 4b you can figure out when it's a good idea to plant flowering kale by referring to the USDA zone info.

Planting Calendar for Flowering Kale

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

You can plant flowering kale a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant flowering kale 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 flowering kale and expect a good harvest is probably August. Any later than that and your flowering kale may not have a chance to really do well. Starting your flowering kale indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Zone 4b. You should expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind 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 Zone 4b and it is different every year. Half of the time in Zone 4b you get a frost after May 15 so make sure that you are prepared to protect your flowering kale if you have 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 your other planting guides for Zone 4b.