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.

The USDA zone info for Detroit can be read to estimate when it's the best time 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 moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant sorrel in Detroit 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

The average date of last frost is April 15 in Detroit. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Detroit and it is different every year. Half of the time in Detroit you get surprised by a frost after April 15 so just be sure to be ready to protect your sorrel if you have a surprise late frost.

USDA Zone Info for Detroit

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Detroit

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