The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Decorah should be read to figure out when it's possible 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.

You can plant lysimachia a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant lysimachia in Decorah 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 grow to maturity. Starting your lysimachia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Decorah 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.

Since the USDA zone info for Decorah is just an average the actual date of last frost is different every year. Since half of the time in Decorah last frost occurs after May 15 be ready to protect your lysimachia in the event of one of those late frosts.

USDA Zone Info for Decorah

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 Decorah

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