Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Northbrook can be looked at to figure out when it's a good idea to plant verbena.

Planting Calendar for Verbena

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

Since verbena do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant verbena 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 verbena and expect a good harvest is probably August. Any later than that and your verbena may not have a chance to really do well. You can get started a couple of weeks earlier by starting your verbena indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Northbrook. In the coldest months of winter you should 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 is different every year. Since half of the time in Northbrook you get a frost after April 15 be ready to cover your verbena 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.