One of the first steps you take when you are estimating your gardening schedule is find your 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.

In Columbia you can determine when it's the best time to plant iceberg lettuce by referring to 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 are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant iceberg lettuce in Columbia 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. If you wait any later than that and your iceberg lettuce may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your iceberg lettuce indoors.

Last Frost Date

In Columbia the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Columbia and it changes from year to year. Since half of the time in Columbia last frost occurs after April 15 be ready to cover your iceberg lettuce if you have a late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Columbia

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