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

A way of figuring out when you can plant sorrel is to consult the USDA zone info for Woburn.

Planting Calendar for Sorrel

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

Sorrel do well in moderate cold which means that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant sorrel in Woburn 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 sorrel and expect a good harvest is probably September. You probably don't want to wait any later than that or else your sorrel may not have a chance to grow to maturity. If you are starting your sorrel indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Woburn the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Woburn is an average and the actual date of last frost will vary from year to year. Half of the time in Woburn it frosts late in the year after April 15 so make sure that you are prepared to cover your sorrel in the event of a late frost.

USDA Zone Info for Woburn

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 Woburn

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