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

The earliest that you can plant four-o-clock flower in Madison can be figured out by looking at the USDA zone info.

Planting Calendar for Four-o-clock flower

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

Four-o-clock flower are not cold tolerant which means that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower in Madison is May. However, you really should wait until June 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 grow to maturity. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Madison. You should expect an average low temperature of -25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Madison is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Madison last frost occurs after May 15 be ready to cover your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Madison

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Madison

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