When to Plant Rosemary in Mchenry, IL

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant rosemary in Mchenry should be determined by looking at 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 quite a bit 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 Mchenry 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. You probably don't want to wait any later than that or else your rosemary may not have a chance to really do well. 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 Mchenry. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Mchenry is an average the actual date of last frost will vary from year to year. Since half of the time in Mchenry you get surprised by a frost after April 15 be ready to protect your rosemary if you have one of those late frosts.

USDA Zone Info for Mchenry

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 Mchenry

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