One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant hollyhocks in Lisle should be determined by looking at 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 do well in moderate cold which means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant hollyhocks in Lisle 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. You can get started a few weeks earlier by starting your hollyhocks indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Lisle. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Lisle may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Lisle there is a last frost after April 15 so make sure that you are prepared to protect your hollyhocks in the event of one of those late frosts.

USDA Zone Info for Lisle

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 Lisle

You may be interested in your other planting guides for Lisle.