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 best time to plant napa cabbage in South Portland should be figured out by checking out 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.

Napa cabbage do well in quite a bit of cold which tells us that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant napa cabbage in South Portland 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 really do well. Starting your napa cabbage indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in South Portland. It might get as low as -15°F during the coldest months of winter.

It's important to remember that USDA zone info for South Portland may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in South Portland last frost occurs after April 15 so make sure that you are ready to cover your napa cabbage in the event of one of those late frosts.

USDA Zone Info for South Portland

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 South Portland

You may be interested in your other planting guides for South Portland.