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.

One way of getting a good idea when you can plant hollyhocks is to look at the USDA zone info for North Chicago.

Planting Calendar for Hollyhocks

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

Hollyhocks do well in a little bit of cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant hollyhocks in North Chicago 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. If you wait any later than that and your hollyhocks may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your hollyhocks indoors.

Last Frost Date

The average date of last frost is April 15 in North Chicago. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for North Chicago may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in North Chicago you get a frost after April 15 be ready to cover your hollyhocks if you have a late frost.

USDA Zone Info for North Chicago

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 North Chicago

You may be interested in your other planting guides for North Chicago.