Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Missoula you should be able to determine when 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.

Lysimachia can survive in some cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant lysimachia in Missoula is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant lysimachia and expect a good harvest is probably September. Any later than that and your lysimachia may not have a chance to fully mature. Starting your lysimachia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Missoula may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Missoula you get a frost after April 15 so just be sure to be ready to protect your lysimachia if you have a late frost.

USDA Zone Info for Missoula

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Missoula

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