One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's possible to plant hardy hibiscus by reviewing the USDA zone info for Cambridge.

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 do well in quite a bit of cold which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant hardy hibiscus in Cambridge 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 really do well. You can get started a few weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

In Cambridge the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Since the USDA zone info for Cambridge may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Cambridge you get surprised by a frost after May 15 be ready to cover your hardy hibiscus if you have a late frost.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Cambridge

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