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

You should be able to determine when to plant sorrel by using the USDA zone info for Alton.

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 bit earlier in the year because they do well in moderate cold.

The earliest that you can plant sorrel in Alton 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. Any later than that and your sorrel may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sorrel indoors.

Last Frost Date

The average date of last frost is April 15 in Alton. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Alton is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Alton there is a last frost after April 15 be ready to protect your sorrel if you have a surprise late frost.

USDA Zone Info for Alton

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 Alton

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