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 checking out the USDA zone info for Northfield you will be able to figure out when you can plant hardy hibiscus.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus are very cold tolerant which means that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant hardy hibiscus in Northfield 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 hardy hibiscus and expect a good harvest is probably August. If you wait any later than that and your hardy hibiscus may not have a chance to grow to maturity. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Northfield the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that USDA zone info for Northfield may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Northfield you get surprised by a frost after May 15 so make sure that you are ready to cover your hardy hibiscus in the event of a late frost.

USDA Zone Info for Northfield

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Northfield

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