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

You should be able to estimate when it's possible to plant dianthus by reviewing the USDA zone info for Billings.

Planting Calendar for Dianthus

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

Dianthus are moderately cold tolerant which tells us that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant dianthus in Billings 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. If you wait any later than that and your dianthus may not have a chance to really do well. Starting your dianthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Billings the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that USDA zone info for Billings may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Billings there is a last frost after May 15 be ready to protect your dianthus if you have a late frost.

USDA Zone Info for Billings

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 Billings

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