When to Plant Dahlias in Naperville, IL

One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant dahlias in Naperville can be figured out by looking at the USDA zone info.


Planting Calendar for Dahlias

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

You really shouldn't plant dahlias until after the last frost when the weather gets warmer because they require warm 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 Naperville 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. If you wait any later than that and your dahlias may not have a chance to really do well. If you are starting your dahlias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Naperville the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Remember that USDA zone info for Naperville is just an average and the actual date of last frost will vary from year to year. Since half of the time in Naperville there is a last frost after April 15 be ready to protect your dahlias if you have a surprise late frost.

USDA Zone Info for Naperville

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 Naperville

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