The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Coralville can be reffered to in order to figure out when it's a good idea to plant verbena.

Planting Calendar for Verbena

Frost tolerance for verbena:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since verbena are barely cold tolerant you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant verbena in Coralville 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 verbena and expect a good harvest is probably August. If you wait any later than that and your verbena may not have a chance to grow to maturity. Starting your verbena 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. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Coralville is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Coralville you get surprised by a frost after April 15 so just be sure to be ready to protect your verbena if you have 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.