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 first opportunity to plant nierembergia in Plymouth should be estimated by referring to the USDA zone info.

Planting Calendar for Nierembergia

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

Since nierembergia require warm weather it's important to wait until after the last frost before you can plant them.

The earliest that you can plant nierembergia in Plymouth 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. If you wait any later than that and your nierembergia may not have a chance to really do well. You can get started a few weeks earlier by starting your nierembergia indoors.

Last Frost Date

In Plymouth 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 USDA zone info for Plymouth is an average and the actual date of last frost will vary from year to year. Since half of the time in Plymouth you get surprised by a frost after April 15 be ready to protect your nierembergia if you have a surprise late frost.

USDA Zone Info for Plymouth

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 Plymouth

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