One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Zone 3b you can figure out when it's the best time 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 the last frost has passed.

It's probably a bad idea to plant tropical hibiscus until after the last frost has passed because they require warm weather.

The earliest that you can plant tropical hibiscus in Zone 3b is May. However, you really should wait until June 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. You probably don't want to wait any later than that or else your tropical hibiscus may not have a chance to really do well. If you are starting your tropical hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 3b. It might get as low as -35°F during the coldest months of winter.

Remember that USDA zone info for Zone 3b is an average and the actual date of last frost is different every year. Half of the time in Zone 3b it frosts late in the year after May 15 so always be ready to cover your tropical hibiscus if you have a late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.