When to Plant Dahlias in Carbondale, IL

One of the best tools that you have as gardeners to help us determine 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 best time to plant dahlias in Carbondale can be figured out by referring to the USDA zone info.


Planting Calendar for Dahlias

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

It's not a good idea to plant dahlias until after the last frost when the weather gets warmer because they do not do well in cold weather.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant dahlias
Possibly ok, but a risky time to plant dahlias
Probably not a good time to plant dahlias

The earliest that you can plant dahlias in Carbondale 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 fully mature. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Carbondale the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Carbondale is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Carbondale it frosts late in the year after April 15 so just be sure to be ready to protect your dahlias if you have a late frost.

USDA Zone Info for Carbondale

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Carbondale

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