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 Kenai should be reffered to in order to figure out when you can plant catharanthus.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Catharanthus are not cold tolerant which means that you need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in Kenai is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your catharanthus may not have a chance to really do well. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

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

Remember that USDA zone info for Kenai is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Kenai you get a frost after May 15 be ready to cover your catharanthus in the event of one of those late frosts.

USDA Zone Info for Kenai

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 Kenai

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