The USDA Zone info is a great tool for gardeners to help us figure out 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.

In Oak Ridge you can determine when it's the best time to plant four o' clock by reviewing the USDA zone info.

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 need to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Oak Ridge 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. You probably don't want to wait any later than that or else your four o' clock may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your four o' clock indoors.

Last Frost Date

The average date of last frost is April 15 in Oak Ridge. It might get as low as 0°F during the coldest months of winter.

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 Oak Ridge and it will vary from year to year. Since half of the time in Oak Ridge you get surprised by a frost after April 15 be ready to cover your four o' clock in the event of one of those late frosts.

USDA Zone Info for Oak Ridge

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Oak Ridge

You may be interested in your other planting guides for Oak Ridge.