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.

In Billings you can determine when to plant tritoma by reviewing the USDA zone info.

Planting Calendar for Tritoma

Frost tolerance for tritoma:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Tritoma tend to make it in cold weather which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant tritoma 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 tritoma and expect a good harvest is probably August. If you wait any later than that and your tritoma may not have a chance to really do well. Starting your tritoma indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Billings and it can change quite a bit from year to year. Since half of the time in Billings there is a last frost after May 15 be ready to protect your tritoma if you have a surprise 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.