Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when to plant dahlias is to use the USDA zone info for Park Forest.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant dahlias until after the last frost because they do not do well in cold weather.

The earliest that you can plant dahlias in Park Forest 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 dahlias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your dahlias indoors.

Last Frost Date

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

Since the USDA zone info for Park Forest is just an average the actual date of last frost changes from year to year. Since half of the time in Park Forest it frosts late in the year after April 15 be ready to protect your dahlias if you have a surprise late frost.

USDA Zone Info for Park Forest

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 Park Forest

You may be interested in your other planting guides for Park Forest.