Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when it's a good idea to plant four o' clock is to examine the USDA zone info for Columbus.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Four O' Clock require warm weather which tells us that you must wait until it warms up after the last frost before you can plant them.

The earliest that you can plant four o' clock in Columbus 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 and expect a good harvest is probably August. If you wait any later than that and your four o' clock may not have a chance to fully mature. Starting your four o' clock indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Columbus. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Columbus is just an average the actual date of last frost will vary from year to year. Since half of the time in Columbus you get a frost after April 15 be ready to cover your four o' clock if you have a late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Columbus

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