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 estimating when it's possible to plant iceberg lettuce is to use the USDA zone info for Douglas.

Planting Calendar for Iceberg lettuce

Frost tolerance for iceberg lettuce:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant iceberg lettuce a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant iceberg lettuce in Douglas is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant iceberg lettuce and expect a good harvest is probably August. You probably don't want to wait any later than that or else your iceberg lettuce may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your iceberg lettuce indoors.

Last Frost Date

On average the last frost is on May 15 in Douglas. You can expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Douglas is not always accurate and the actual date of last frost is different every year. Half of the time in Douglas you get surprised by a frost after May 15 so be sure to be ready to cover your iceberg lettuce in the event of one of those late frosts.

USDA Zone Info for Douglas

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Douglas

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