The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when you can plant four o' clock is to refer to the USDA zone info for Ames.

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 not a good idea to plant four o' clock until after the last frost has passed because they require warm weather.

The earliest that you can plant four o' clock in Ames 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 really do well. If you are starting your four o' clock indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ames the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Ames and it will vary from year to year. Half of the time in Ames there is a last frost after April 15 so make sure that you are ready to cover your four o' clock if you have a surprise late frost.

USDA Zone Info for Ames

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ames

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