One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Elk River you should be able to figure out when you can 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.

You can plant verbena slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant verbena in Elk River 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 verbena and expect a good harvest is probably August. Any later than that and 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 couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Elk River. It might get as low as -25°F during the coldest months of winter.

It's important to remember that USDA zone info for Elk River is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Elk River there is a last frost after May 15 so be sure to be ready to cover your verbena in the event of a late frost.

USDA Zone Info for Elk River

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Elk River

You may be interested in your other planting guides for Elk River.