One of the best tools that you have as gardeners to help us figure out 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.

By referring to the USDA zone info for Dover you should be able to estimate when you can plant napa cabbage.

Planting Calendar for Napa cabbage

Frost tolerance for napa cabbage:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

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

The earliest that you can plant napa cabbage in Dover 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 napa cabbage and expect a good harvest is probably September. You probably don't want to wait any later than that or else your napa cabbage may not have a chance to really do well. If you are starting your napa cabbage indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Dover. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Dover is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Dover last frost occurs after April 15 be ready to cover your napa cabbage if you have a late frost.

USDA Zone Info for Dover

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 Dover

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