One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The first chance to plant rosemary in Flossmoor should be estimated 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 do well in cold you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Flossmoor 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. Any later than that and your rosemary may not have a chance to fully mature. If you are starting your rosemary indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Flossmoor is not always accurate and the actual date of last frost changes from year to year. Half of the time in Flossmoor last frost occurs after April 15 so always be ready to cover your rosemary if you have a surprise late frost.

USDA Zone Info for Flossmoor

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 Flossmoor

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