One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when you can plant lettuce is to consult the USDA zone info for Zone 4a.

Planting Calendar for Lettuce

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

Lettuce can survive in moderate cold which means that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant lettuce in Zone 4a 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. Any later than that and your lettuce may not have a chance to grow to maturity. Starting your lettuce indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. You should expect an average low temperature of -30°F in 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 Zone 4a and it is different every year. Since half of the time in Zone 4a it frosts late in the year after May 15 be ready to cover your lettuce in the event of one of those late frosts.

USDA Zone Info for Zone 4a

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 Zone 4a

You may be interested in your other planting guides for Zone 4a.