When to Plant Mimulus in Naperville, 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 zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant mimulus in Naperville can be estimated by reviewing the USDA zone info.


Planting Calendar for Mimulus

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

It's a bad idea to plant mimulus 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 mimulus
Possibly ok, but a risky time to plant mimulus
Probably not a good time to plant mimulus

The earliest that you can plant mimulus 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 mimulus and expect a good harvest is probably August. Any later than that and your mimulus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your mimulus indoors.

Last Frost Date

On average the last frost is on April 15 in Naperville. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Naperville is an average the actual date of last frost changes from year to year. Half of the time in Naperville there is a last frost after April 15 so always be ready to cover your mimulus in the event of one of those late frosts.

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.