One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Highland Park can be reviewed to estimate when it's possible to plant common hollyhock.

Planting Calendar for Common hollyhock

Frost tolerance for common hollyhock:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Common hollyhock do ok in some cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock in Highland Park 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 common hollyhock and expect a good harvest is probably September. If you wait any later than that and your common hollyhock may not have a chance to really do well. Starting your common hollyhock indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Highland Park the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Highland Park is an average the actual date of last frost changes from year to year. Half of the time in Highland Park there is a last frost after April 15 so always be ready to protect your common hollyhock in the event of one of those late frosts.

USDA Zone Info for Highland Park

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Highland Park

You may be interested in your other planting guides for Highland Park.