One of the best tools that you have as gardeners to help us determine 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.

One way of making a decision about when it's the best time to plant nierembergia is to look at the USDA zone info for Plymouth.

Planting Calendar for Nierembergia

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

You should not plant nierembergia until after the last frost has passed because they do not do well in cold weather.

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. You probably don't want to wait any later than that or else your nierembergia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your nierembergia indoors.

Last Frost Date

In Plymouth the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Plymouth is just an average and the actual date of last frost is different every year. Since half of the time in Plymouth last frost occurs after April 15 be ready to cover your nierembergia if you have one of those late frosts.

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.