Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's possible to plant black eyed susans in Great Falls by reviewing the USDA zone info.

Planting Calendar for Black Eyed Susans

Frost tolerance for black eyed susans:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since black eyed susans do not do well in cold weather it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant black eyed susans in Great Falls is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant black eyed susans and expect a good harvest is probably August. Any later than that and your black eyed susans may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your black eyed susans indoors.

Last Frost Date

On average the last frost is on May 15 in Great Falls. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Great Falls is an average the actual date of last frost is different every year. Since half of the time in Great Falls it frosts late in the year after May 15 be ready to cover your black eyed susans in the event of one of those late frosts.

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.