The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Watertown should be used to figure out when to plant romaine lettuce.

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 ok in a bit of cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant romaine lettuce in Watertown 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. If you wait any later than that and your romaine lettuce may not have a chance to grow to maturity. Starting your romaine lettuce indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Watertown and it can change quite a bit from year to year. Since half of the time in Watertown last frost occurs after April 15 be ready to protect your romaine lettuce in the event of one of those late frosts.

USDA Zone Info for Watertown

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 Watertown

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