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 will be able to estimate when it's the best time to plant lettuce by looking at the USDA zone info for Iron Mountain.

Planting Calendar for Lettuce

Frost tolerance for lettuce:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Lettuce are moderately cold tolerant which tells us that you can get them planted earlier than other frost tender plants.

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

Last Frost Date

On average all chance of frost has passed is on May 15 in Iron Mountain. It might get as low as -30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Iron Mountain and it will vary from year to year. Half of the time in Iron Mountain last frost occurs after May 15 so make sure that you are prepared to protect your lettuce if you have a late frost.

USDA Zone Info for Iron Mountain

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 Iron Mountain

You may be interested in your other planting guides for Iron Mountain.