One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

By looking at the USDA zone info for Northbrook it's possible 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.

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

The earliest that you can plant sorrel in Northbrook 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 fully mature. You can get started a couple of weeks earlier by starting your sorrel indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Northbrook. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Northbrook is just an average the actual date of last frost changes from year to year. Half of the time in Northbrook you get surprised by a frost after April 15 so just be sure to be ready to cover your sorrel in the event of one of those late frosts.

USDA Zone Info for Northbrook

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 Northbrook

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