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.

The USDA zone info for Zimmerman should be reffered to in order to figure out when it's the best time 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 has passed.

It's a bad idea to plant four o' clock until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant four o' clock in Zimmerman 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 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 fully mature. Starting your four o' clock indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Zimmerman. You can expect an average low temperature of -30°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Zimmerman and it can change quite a bit from year to year. Since half of the time in Zimmerman you get surprised by a frost after May 15 be ready to protect your four o' clock if you have a surprise late frost.

USDA Zone Info for Zimmerman

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zimmerman

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