The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 Glendale Heights can be reffered to in order to determine when it's the best time to plant hollyhocks.

Planting Calendar for Hollyhocks

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

You can plant hollyhocks a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant hollyhocks in Glendale Heights 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. If you are starting your hollyhocks indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Glendale Heights the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

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 Glendale Heights and it changes from year to year. Since half of the time in Glendale Heights last frost occurs after April 15 be ready to cover your hollyhocks if you have a surprise late frost.

USDA Zone Info for Glendale Heights

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 Glendale Heights

You may be interested in your other planting guides for Glendale Heights.