When to Plant Dahlias in Wilmette, IL

One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

A common way of making a decision about when it's possible to plant dahlias is to consult the USDA zone info for Wilmette.


Planting Calendar for Dahlias

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

Since dahlias require warm weather you must wait until after the last frost 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 Wilmette 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 really do well. If you are starting your dahlias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Wilmette. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Wilmette and it can change quite a bit from year to year. Since half of the time in Wilmette you get surprised by a frost after April 15 be ready to protect your dahlias in the event of a late frost.

USDA Zone Info for Wilmette

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 Wilmette

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