One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when to plant iceberg lettuce is to look at the USDA zone info for Spearfish.

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.

Since iceberg lettuce are barely cold tolerant you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant iceberg lettuce in Spearfish 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 grow to maturity. If you are starting your iceberg lettuce indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Spearfish. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for Spearfish may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Spearfish you get a frost after April 15 so make sure that you are ready to cover your iceberg lettuce in the event of a late frost.

USDA Zone Info for Spearfish

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 Spearfish

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