One of the first steps you take when you are getting a good idea 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.

A way of estimating when it's the best time to plant common hollyhock is to use the USDA zone info for Forest Park.

Planting Calendar for Common hollyhock

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

You can plant common hollyhock a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant common hollyhock in Forest 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. If you are starting your common hollyhock indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Forest Park. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Forest Park is an average the actual date of last frost will vary from year to year. Half of the time in Forest Park you get surprised by a frost after April 15 so be sure to be ready to cover your common hollyhock in the event of one of those late frosts.

USDA Zone Info for Forest Park

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Forest Park

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