The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Coralville you can estimate when it's the best time to plant torenia by looking at the USDA zone info.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant torenia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant torenia in Coralville is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant torenia and expect a good harvest is probably August. If you wait any later than that and your torenia may not have a chance to fully mature. Starting your torenia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Coralville. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that USDA zone info for Coralville may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Coralville you get surprised by a frost after April 15 be ready to protect your torenia in the event of a 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.