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.

You will be able to figure out when it's possible to plant napa cabbage by checking out the USDA zone info for Ironwood.

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 cold which tells us that you can plant them much earlier than more sensitive plants.

The earliest that you can plant napa cabbage in Ironwood is March. However, you really should wait until April 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 August. If you wait any later than that and your napa cabbage may not have a chance to grow to maturity. Starting your napa cabbage indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Ironwood. You can expect an average low temperature of -30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Ironwood and it changes from year to year. Half of the time in Ironwood there is a last frost after May 15 so make sure that you are ready to cover your napa cabbage if you have a surprise late frost.

USDA Zone Info for Ironwood

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Ironwood

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