The USDA Zone info is a great tool for gardeners to help us estimate 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 Riverton should be read to figure out when it's the best time to plant vinca vine.

Planting Calendar for Vinca Vine

Frost tolerance for vinca vine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since vinca vine are moderately cold tolerant you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant vinca vine in Riverton is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant vinca vine and expect a good harvest is probably August. Any later than that and your vinca vine may not have a chance to grow to maturity. If you are starting your vinca vine indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Riverton. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that USDA zone info for Riverton is an average and the actual date of last frost changes from year to year. Since half of the time in Riverton you get surprised by a frost after May 15 be ready to cover your vinca vine in the event of one of those late frosts.

USDA Zone Info for Riverton

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Riverton

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