Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. 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 determining when it's the best time to plant iceberg lettuce is to consult the USDA zone info for Gypsum.

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 just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant iceberg lettuce in Gypsum 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 iceberg lettuce and expect a good harvest is probably August. Any later than that and your iceberg lettuce may not have a chance to really do well. You can get started a few weeks earlier by starting your iceberg lettuce indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Gypsum. In the coldest months of winter you should expect an average low temperature of -20°F.

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 Gypsum and it is different every year. Half of the time in Gypsum there is a last frost after April 15 so make sure that you are ready to protect your iceberg lettuce if you have a late frost.

USDA Zone Info for Gypsum

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 Gypsum

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