When to Plant Dahlias in Flossmoor, IL

Before planting it is a good idea to find your USDA Zone info to figure out 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.

The USDA zone info for Flossmoor should be reviewed to figure out when it's the best time to plant dahlias.


Planting Calendar for Dahlias

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

Dahlias do not do well in cold weather which tells us that you must wait until it warms up after the last frost when the weather gets warmer before you can plant them.

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 Flossmoor 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 grow to maturity. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Flossmoor. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Flossmoor is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Flossmoor it frosts late in the year after April 15 be ready to protect your dahlias in the event of one of those late frosts.

USDA Zone Info for Flossmoor

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 Flossmoor

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