The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's possible to plant catharanthus by using the USDA zone info for Hannibal.

Planting Calendar for Catharanthus

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

It's a bad idea to plant catharanthus until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant catharanthus in Hannibal 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 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 grow to maturity. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

The average date of last frost is April 15 in Hannibal. You should expect an average low temperature of -10°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Hannibal and it will vary from year to year. Half of the time in Hannibal it frosts late in the year after April 15 so be sure to be ready to cover your catharanthus if you have a surprise late frost.

USDA Zone Info for Hannibal

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Hannibal

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