One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant trachelium in Billings should be determined by reviewing the USDA zone info.

Planting Calendar for Trachelium

Frost tolerance for trachelium:	Not tolerant of frost.
When to plant:	After the last frost.

Trachelium require warm weather which tells us that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant trachelium in Billings 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 trachelium and expect a good harvest is probably August. If you wait any later than that and your trachelium may not have a chance to grow to maturity. If you are starting your trachelium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Billings. In the coldest months of winter you can expect an average low temperature of -25°F.

Remember that USDA zone info for Billings is just an average and the actual date of last frost will vary from year to year. Since half of the time in Billings it frosts late in the year after May 15 be ready to protect your trachelium 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.