One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. 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 Columbia can be read to estimate when it's a good idea to plant four o' clock.

Planting Calendar for Four O' Clock

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

It's probably not a good idea to plant four o' clock until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant four o' clock in Columbia 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. If you are starting your four o' clock indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Columbia. It might get as low as 10°F during the coldest months of winter.

Always keep in mind that USDA zone info for Columbia is an average and the actual date of last frost is different every year. Half of the time in Columbia you get surprised by a frost after March 15 so make sure that you are prepared to cover your four o' clock in the event of one of those late frosts.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Columbia

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