Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Billings it's a good idea to determine when it's a good idea to plant lysimachia.

Planting Calendar for Lysimachia

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

Since lysimachia are one of those plants that can tolerate a little bit of cold weather 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 lysimachia 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 lysimachia and expect a good harvest is probably August. If you wait any later than that and your lysimachia may not have a chance to really do well. Starting your lysimachia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Billings. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that USDA zone info for Billings is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Billings last frost occurs after May 15 so always be ready to protect your lysimachia if you have one of those late frosts.

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.