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.

The first chance to plant verbena in Dubuque can be estimated by checking out the USDA zone info.

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 a bit earlier in the year than more sensitive plants.

The earliest that you can plant verbena in Dubuque 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. You probably don't want to wait any later than that or else your verbena may not have a chance to fully mature. If you are starting your verbena indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Dubuque. It might get as low as -20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Dubuque 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 Dubuque you get surprised by a frost after April 15 be ready to cover your verbena in the event of a surprise late frost.

USDA Zone Info for Dubuque

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Dubuque

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