One of the best tools that you have as gardeners to help us determine 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 best time to plant lettuce in Waterloo can be estimated by checking out the USDA zone info.

Planting Calendar for Lettuce

Frost tolerance for lettuce:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

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

The earliest that you can plant lettuce in Waterloo is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant lettuce and expect a good harvest is probably September. Any later than that and your lettuce may not have a chance to fully mature. If you are starting your lettuce indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Waterloo. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Waterloo may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Waterloo it frosts late in the year after April 15 so make sure that you are prepared to cover your lettuce in the event of one of those late frosts.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Waterloo

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