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 first opportunity to plant verbena in Great Falls can be figured out by referring to 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.

Verbena are barely cold tolerant which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant verbena in Great Falls 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. You probably don't want to wait any later than that or else your verbena may not have a chance to grow to maturity. 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 May 15 in Great Falls. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Great Falls is just an average the actual date of last frost is different every year. Half of the time in Great Falls you get surprised by a frost after May 15 so just be sure to be ready to protect your verbena in the event of a surprise late frost.

USDA Zone Info for Great Falls

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Great Falls

You may be interested in your other planting guides for Great Falls.