When to Plant Thyme in Naperville, IL

One of the first steps you take when you are figuring out 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.

By referring to the USDA zone info for Naperville it's a good idea to determine when it's the best time to plant thyme.


Planting Calendar for Thyme

Frost tolerance for thyme: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Thyme are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them much earlier than other plants that might not handle the cold.

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

The earliest that you can plant thyme in Naperville is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant thyme and expect a good harvest is probably September. You probably don't want to wait any later than that or else your thyme may not have a chance to fully mature. You can get started a few weeks earlier by starting your thyme indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Naperville. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Naperville is just an average 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 thyme if you have 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.