Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when it's a good idea to plant hardy hibiscus is to use the USDA zone info for Coralville.

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 tells us that 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 Coralville 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. You probably don't want to wait any later than that or else 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

On average the last frost has passed is on April 15 in Coralville. It might get as low as -15°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Coralville and it is different every year. Since half of the time in Coralville it frosts late in the year after April 15 be ready to protect your hardy hibiscus if you have a surprise late frost.

USDA Zone Info for Coralville

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Coralville

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