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.

The first opportunity to plant nierembergia in Somerville should be figured out by using the USDA zone info.

Planting Calendar for Nierembergia

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

Nierembergia require warm weather which tells us that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Somerville 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 little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Somerville. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that USDA zone info for Somerville is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Somerville you get a frost after April 15 be ready to protect your nierembergia in the event of a late frost.

USDA Zone Info for Somerville

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Somerville

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