One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Herrin should be read to figure out when it's possible 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.

Verbena do well in very little cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant verbena in Herrin 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. Any later than that and your verbena may not have a chance to really do well. You can get started a couple of weeks earlier by starting your verbena indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Herrin. In the coldest months of winter you should expect an average low temperature of -5°F.

Just be sure to remember that USDA zone info for Herrin may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Herrin 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 Herrin

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Herrin

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