Before planting it is a good idea to find your USDA Zone info to figure out 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.

In Stillwater you can determine when you can plant nierembergia by using the USDA zone info.

Planting Calendar for Nierembergia

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

Since nierembergia are not cold tolerant you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Stillwater 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. Any later than that and your nierembergia may not have a chance to fully mature. You can get started a few weeks earlier by starting your nierembergia indoors.

Last Frost Date

The average date of last frost is May 15 in Stillwater. In the coldest months of winter you should expect an average low temperature of -25°F.

It's important to remember that USDA zone info for Stillwater is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Stillwater there is a last frost after May 15 be ready to cover your nierembergia if you have a surprise late frost.

USDA Zone Info for Stillwater

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 Stillwater

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