One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant romaine lettuce in Waterloo should be determined by using the USDA zone info.

Planting Calendar for Romaine lettuce

Frost tolerance for romaine lettuce:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Romaine lettuce do well in cold which tells us that you can plant them much earlier than other plants that might not handle the cold.

The earliest that you can plant romaine 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 romaine lettuce and expect a good harvest is probably September. Any later than that and your romaine lettuce may not have a chance to really do well. Starting your romaine lettuce indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Waterloo and it is different every year. Half of the time in Waterloo it frosts late in the year after April 15 so be sure to be ready to protect your romaine lettuce in the event of one of those late frosts.

USDA Zone Info for Waterloo

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 Waterloo

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