One of the first steps you take when you are getting a good idea 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.

By referring to the USDA zone info for Rhinelander you should be able to determine when it's the best time to 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.

Since hardy hibiscus do well in cold you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy hibiscus in Rhinelander 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 couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Rhinelander. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Rhinelander is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Rhinelander you get surprised by a frost after May 15 be ready to protect your hardy hibiscus in the event of one of those late frosts.

USDA Zone Info for Rhinelander

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 Rhinelander

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