One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Duluth you can figure out when it's the best time to plant hardy hibiscus by referring to the USDA zone info.

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 one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them a quite a bit earlier than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus in Duluth is February. However, you really should wait until March 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 September. 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 couple of weeks earlier.

Last Frost Date

In Duluth the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 5°F.

Since the USDA zone info for Duluth is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Duluth last frost occurs after April 15 so be sure to be ready to cover your hardy hibiscus if you have a late frost.

USDA Zone Info for Duluth

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Duluth

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