When to Plant Rosemary in Carol Stream, IL

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

The best time to plant rosemary in Carol Stream can be figured out by referring to the USDA zone info.


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 very cold tolerant you can plant them much earlier in the year than other frost tender 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 Carol Stream 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 fully mature. You can get started a few weeks earlier by starting your rosemary indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Carol Stream. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Carol Stream is not always accurate the actual date of last frost is different every year. Since half of the time in Carol Stream it frosts late in the year after April 15 be ready to cover your rosemary if you have one of those late frosts.

USDA Zone Info for Carol Stream

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 Carol Stream

You may be interested in your other planting guides for Carol Stream.