Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Westminster can be looked at to figure out when it's a good idea to plant bok choi.

Planting Calendar for Bok Choi

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

Since bok choi do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant bok choi in Westminster 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. You probably don't want to wait any later than that or else your bok choi may not have a chance to really do well. If you are starting your bok choi indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Westminster the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Westminster is an average the actual date of last frost is different every year. Since half of the time in Westminster there is a last frost after April 15 be ready to cover your bok choi in the event of one of those late frosts.

USDA Zone Info for Westminster

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Westminster

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