The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant dianthus in Great Falls should be figured out by using the USDA zone info.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Dianthus do ok in mild cold which tells us that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant dianthus in Great Falls 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 dianthus and expect a good harvest is probably August. Any later than that and your dianthus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your dianthus indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Great Falls and it is different every year. Half of the time in Great Falls there is a last frost after May 15 so always be ready to protect your dianthus 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.