The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Northbrook you can determine when it's a good idea to plant tropical hibiscus by using the USDA zone info.

Planting Calendar for Tropical Hibiscus

Frost tolerance for tropical hibiscus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Tropical Hibiscus require warm weather which tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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

The last month that you can plant tropical hibiscus and expect a good harvest is probably August. If you wait any later than that and your tropical hibiscus may not have a chance to fully mature. You can get started a little bit earlier by starting your tropical hibiscus indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Northbrook is just an average and the actual date of last frost will vary from year to year. Half of the time in Northbrook there is a last frost after April 15 so be sure to be ready to cover your tropical hibiscus in the event of a surprise 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.