One of the first steps you take when you are making a decision about your gardening schedule is find your 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 Yorkville can be used to figure out when 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.

Since four-o-clock flower are not cold tolerant it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower in Yorkville 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 really do well. Starting your four-o-clock flower indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Yorkville the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Yorkville is an average the actual date of last frost changes from year to year. Since half of the time in Yorkville you get a frost after April 15 be ready to protect your four-o-clock flower if you have a surprise late frost.

USDA Zone Info for Yorkville

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Yorkville

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