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.

The first chance to plant bok choi in Great Falls can be estimated by reviewing the USDA zone info.

Planting Calendar for Bok Choi

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

Bok Choi do ok in a little bit of cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

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

Last Frost Date

The average date of last frost is May 15 in Great Falls. You can expect an average low temperature of -30°F in the coldest months of winter.

It's important to remember that USDA zone info for Great Falls is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Great Falls last frost occurs after May 15 so make sure that you are ready to cover your bok choi in the event of one of those late frosts.

USDA Zone Info for Great Falls

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 Great Falls

You may be interested in your other planting guides for Great Falls.