One of the first steps you take when you are estimating 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 Coralville you can determine when you can plant cardinal flower by looking at the USDA zone info.

Planting Calendar for Cardinal Flower

Frost tolerance for cardinal flower:	Not tolerant of frost.
When to plant:	After the last frost.

Since cardinal flower do not do well in cold weather it is important to wait until after the last frost before you can plant them.

The earliest that you can plant cardinal flower 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 cardinal flower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your cardinal flower may not have a chance to fully mature. Starting your cardinal flower indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Coralville may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Coralville you get a frost after April 15 be ready to cover your cardinal flower 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.