Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Nebraska City you should be able to determine when it's the best time to plant periwinkles.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Periwinkles require warm weather which means that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant periwinkles in Nebraska City 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 periwinkles and expect a good harvest is probably August. If you wait any later than that and your periwinkles may not have a chance to really do well. If you are starting your periwinkles indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Nebraska City may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Nebraska City it frosts late in the year after April 15 be ready to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for Nebraska City

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 Nebraska City

You may be interested in your other planting guides for Nebraska City.