One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 Napoleon it's possible to estimate when it's a good idea to plant nierembergia.

Planting Calendar for Nierembergia

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

Nierembergia require warm weather which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant nierembergia in Napoleon is April. However, you really should wait until May 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 grow to maturity. Starting your nierembergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Napoleon. You can expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Napoleon is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Napoleon you get a frost after April 15 so just be sure to be ready to protect your nierembergia if you have one of those late frosts.

USDA Zone Info for Napoleon

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Napoleon

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