The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Northbrook can be reviewed to estimate when it's a good idea to plant tarragon.

Planting Calendar for Tarragon

Frost tolerance for tarragon:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Tarragon are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant tarragon in Northbrook is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tarragon and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tarragon may not have a chance to fully mature. If you are starting your tarragon 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 Northbrook. In the coldest months of winter you should expect an average low temperature of -15°F.

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 Northbrook and it changes from year to year. Half of the time in Northbrook you get surprised by a frost after April 15 so always be ready to protect your tarragon in the event of a late frost.

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.