When to Plant Rosemary in Wilmette, IL

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when it's a good idea to plant rosemary by checking out the USDA zone info for Wilmette.


Planting Calendar for Rosemary

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

Since rosemary are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than more sensitive plants.

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

The earliest that you can plant rosemary in Wilmette 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 rosemary and expect a good harvest is probably September. If you wait any later than that and your rosemary may not have a chance to grow to maturity. Starting your rosemary indoors is a great way to get them started 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.

Always keep in mind that USDA zone info for Wilmette may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Wilmette you get a frost after April 15 so make sure that you are ready to protect your rosemary in the event of a surprise 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.