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

A way of estimating when it's the best time to plant bok choi is to consult the USDA zone info for Flagstaff.

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 are one of those plants that can tolerate a little bit of cold weather which means that you can start planting them earlier than more sensitive plants.

The earliest that you can plant bok choi in Flagstaff is February. However, you really should wait until March 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 September. Any later than that and your bok choi may not have a chance to grow to maturity. If you are starting your bok choi indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Flagstaff. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Flagstaff is an average and the actual date of last frost changes from year to year. Half of the time in Flagstaff you get surprised by a frost after April 15 so make sure that you are ready to cover your bok choi in the event of a surprise late frost.

USDA Zone Info for Flagstaff

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Flagstaff

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