One of the best tools that you have as gardeners to help us estimate 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.

The first opportunity to plant iceberg lettuce in Aspen should be estimated by using the USDA zone info.

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.

Iceberg lettuce do ok in a tiny bit of cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant iceberg lettuce in Aspen 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. If you are starting your iceberg lettuce indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Aspen. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Aspen is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Aspen last frost occurs after April 15 be ready to cover your iceberg lettuce if you have a late frost.

USDA Zone Info for Aspen

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Aspen

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