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.

The USDA zone info for Hannibal can be reviewed to figure out when it's possible to plant four-o-clock flower.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since four-o-clock flower do not do well in cold weather it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant four-o-clock flower 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 four-o-clock flower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

In Hannibal the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Hannibal 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 Hannibal you get surprised by a frost after April 15 be ready to cover your four-o-clock flower in the event of 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.