One of the best tools that you have as gardeners to help us estimate 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.

By looking at the USDA zone info for Watertown it's possible to estimate when it's possible to plant sorrel.

Planting Calendar for Sorrel

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

You can plant sorrel a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant sorrel in Watertown 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 sorrel and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sorrel may not have a chance to fully mature. If you are starting your sorrel indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Watertown. You can expect an average low temperature of -30°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Watertown and it changes from year to year. Half of the time in Watertown there is a last frost after May 15 so be sure to be ready to cover your sorrel in the event of a surprise late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Watertown

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