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.

The first chance to plant lysimachia in Zone 4b should be estimated by reviewing the USDA zone info.

Planting Calendar for Lysimachia

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

Lysimachia do well in some cold which means that 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 Zone 4b 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. Any later than that and your lysimachia may not have a chance to really do well. If you are starting your lysimachia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Zone 4b. In the coldest months of winter you should expect an average low temperature of -25°F.

Always keep in mind that USDA zone info for Zone 4b is just an average and the actual date of last frost will vary from year to year. Half of the time in Zone 4b it frosts late in the year after May 15 so be sure to be ready to protect your lysimachia if you have one of those late frosts.

USDA Zone Info for Zone 4b

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 Zone 4b

You may be interested in your other planting guides for Zone 4b.