The USDA Zone info is a great tool for gardeners to help us figure out 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.

By checking out the USDA zone info for Helena it's a good idea to estimate when you can plant kohlrabi.

Planting Calendar for Kohlrabi

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

Since kohlrabi are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant kohlrabi in Helena 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 kohlrabi and expect a good harvest is probably August. Any later than that and your kohlrabi may not have a chance to really do well. You can get started a few weeks earlier by starting your kohlrabi indoors.

Last Frost Date

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

Since the USDA zone info for Helena is an average the actual date of last frost will vary from year to year. Since half of the time in Helena last frost occurs after May 15 be ready to protect your kohlrabi in the event of one of those late frosts.

USDA Zone Info for Helena

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 Helena

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