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.

The USDA zone info for Winthrop Harbor should be read to figure out 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.

Since sorrel are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant sorrel in Winthrop Harbor 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. If you wait any later than that and your sorrel may not have a chance to really do well. You can get started a few weeks earlier by starting your sorrel indoors.

Last Frost Date

The average date of last frost is April 15 in Winthrop Harbor. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Winthrop Harbor and it is different every year. Half of the time in Winthrop Harbor you get a frost after April 15 so make sure that you are ready to cover your sorrel if you have a surprise late frost.

USDA Zone Info for Winthrop Harbor

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.