The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant napa cabbage in Haverhill by looking at the USDA zone info.

Planting Calendar for Napa cabbage

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

Since napa cabbage do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant napa cabbage in Haverhill 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. Any later than that and your napa cabbage may not have a chance to grow to maturity. 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

On average all chance of frost has passed is on April 15 in Haverhill. In the coldest months of winter you can expect an average low temperature of -10°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Haverhill and it changes from year to year. Half of the time in Haverhill it frosts late in the year after April 15 so always be ready to cover your napa cabbage in the event of a late frost.

USDA Zone Info for Haverhill

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 Haverhill

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