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

You should be able to determine when you can plant four-o-clock flower by using the USDA zone info for Howell.

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 require warm weather which tells us that you have 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 Howell 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. You can get started a little bit earlier by starting your four-o-clock flower indoors.

Last Frost Date

The average date of last frost is April 15 in Howell. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Howell is just an average the actual date of last frost will vary from year to year. Half of the time in Howell you get a frost after April 15 so be sure to be ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Howell

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Howell

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