The USDA Zone info is a great tool for gardeners to help us figure out your gardening 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 Rockton should be used to figure out when to plant nierembergia.

Planting Calendar for Nierembergia

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

It's probably not a good idea to plant nierembergia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant nierembergia in Rockton 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. 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

The average date of last frost is April 15 in Rockton. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Rockton is an average the actual date of last frost will vary from year to year. Half of the time in Rockton last frost occurs after April 15 so just be sure to be ready to cover your nierembergia in the event of a surprise late frost.

USDA Zone Info for Rockton

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 Rockton

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