Before planting it is a good idea to find your USDA Zone info to figure out 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 Forest Lake you should be able to determine when you can plant nierembergia.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since nierembergia require warm weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant nierembergia in Forest Lake is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant nierembergia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nierembergia may not have a chance to fully mature. Starting your nierembergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on May 15 in Forest Lake. You should expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that USDA zone info for Forest Lake is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Forest Lake last frost occurs after May 15 be ready to cover your nierembergia in the event of one of those late frosts.

USDA Zone Info for Forest Lake

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 Forest Lake

You may be interested in your other planting guides for Forest Lake.