One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Zone 6b you will be able to figure out when it's the best time 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 all chance of frost has passed.

Four-o-clock flower are not cold tolerant which means that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant four-o-clock flower in Zone 6b 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. Any later than that and your four-o-clock flower may not have a chance to fully mature. Starting your four-o-clock flower indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Zone 6b the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 6b is just an average and the actual date of last frost is different every year. Half of the time in Zone 6b last frost occurs after April 15 so make sure that you are ready to cover your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Zone 6b

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Zone 6b

You may be interested in your other planting guides for Zone 6b.