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

A common way of getting a good idea when it's the best time to plant dahlias is to examine the USDA zone info for Decatur.

Planting Calendar for Dahlias

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

It's probably a bad idea to plant dahlias until after the last frost because they are not cold tolerant.

The earliest that you can plant dahlias in Decatur 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. Any later than that and your dahlias may not have a chance to fully mature. Starting your dahlias indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Decatur is just an average and the actual date of last frost is different every year. Since half of the time in Decatur there is a last frost after April 15 be ready to cover your dahlias if you have one of those late frosts.

USDA Zone Info for Decatur

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 Decatur

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