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.

The earliest that you can plant romaine lettuce in Idaho Falls can be figured out by checking out the USDA zone info.

Planting Calendar for Romaine lettuce

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

Romaine lettuce are very cold tolerant which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant romaine lettuce in Idaho Falls 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 romaine lettuce and expect a good harvest is probably September. Any later than that and your romaine lettuce may not have a chance to grow to maturity. You can get started a little bit earlier by starting your romaine lettuce indoors.

Last Frost Date

In Idaho Falls the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Since the USDA zone info for Idaho Falls is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Idaho Falls there is a last frost after April 15 so be sure to be ready to cover your romaine lettuce in the event of one of those late frosts.

USDA Zone Info for Idaho Falls

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Idaho Falls

You may be interested in your other planting guides for Idaho Falls.