Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant hollyhocks in Highland Park should be determined by using the USDA zone info.

Planting Calendar for Hollyhocks

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

Hollyhocks are moderately cold tolerant which means that you can plant them earlier than other frost tender plants.

The earliest that you can plant hollyhocks 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 hollyhocks and expect a good harvest is probably September. Any later than that and your hollyhocks may not have a chance to grow to maturity. Starting your hollyhocks indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Highland Park. In the coldest months of winter you should expect an average low temperature of -5°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Highland Park and it changes from year to year. Since half of the time in Highland Park you get surprised by a frost after April 15 be ready to protect your hollyhocks 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.