Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Bourbonnais you can determine when it's a good idea to plant hollyhocks by referring to 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.

You can plant hollyhocks a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant hollyhocks in Bourbonnais 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. You probably don't want to wait any later than that or else your hollyhocks may not have a chance to fully mature. Starting your hollyhocks indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Bourbonnais may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Bourbonnais last frost occurs after April 15 be ready to cover your hollyhocks in the event of a late frost.

USDA Zone Info for Bourbonnais

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 Bourbonnais

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