One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Irmo it's possible to determine when 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 when the weather gets warmer.

Since four o' clock do not do well in cold weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Irmo 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. Any later than that and your four o' clock may not have a chance to really do well. If you are starting your four o' clock indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Irmo the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Irmo and it is different every year. Since half of the time in Irmo there is a last frost after March 15 be ready to cover your four o' clock in the event of a surprise late frost.

USDA Zone Info for Irmo

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 Irmo

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