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.

By using the USDA zone info for Northbrook it's a good idea to figure out when it's possible to plant foxglove.

Planting Calendar for Foxglove

Frost tolerance for foxglove:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

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

The earliest that you can plant foxglove 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 foxglove and expect a good harvest is probably September. Any later than that and your foxglove may not have a chance to fully mature. If you are starting your foxglove indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Northbrook the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Northbrook is not always accurate the actual date of last frost changes from year to year. Half of the time in Northbrook it frosts late in the year after April 15 so always be ready to cover your foxglove if you have 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.