Before planting it is a good idea to find your USDA Zone info to determine your garden 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 Alpena can be read to estimate when it's possible to plant nierembergia.

Planting Calendar for Nierembergia

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

Since nierembergia are not cold tolerant it is important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant nierembergia in Alpena 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 really do well. If you are starting your nierembergia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Alpena the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Alpena and it will vary from year to year. Half of the time in Alpena you get a frost after April 15 so make sure that you are ready to cover your nierembergia in the event of a surprise late frost.

USDA Zone Info for Alpena

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Alpena

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