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

You should not plant nierembergia until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant nierembergia in Leominster 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 fully mature. If you are starting your nierembergia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Leominster. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Leominster is an average the actual date of last frost is different every year. Half of the time in Leominster you get surprised by a frost after April 15 so just be sure to be ready to protect your nierembergia if you have a surprise late frost.

USDA Zone Info for Leominster

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 Leominster

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