One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's a good idea to plant bok choi is to examine the USDA zone info for Princeton.

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 can survive in moderate cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bok choi in Princeton 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. If you wait 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

In Princeton 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 Princeton is not always accurate the actual date of last frost will vary from year to year. Half of the time in Princeton last frost occurs after April 15 so just be sure to be ready to cover your bok choi if you have a surprise late frost.

USDA Zone Info for Princeton

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 Princeton

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