The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant common hollyhock in Warrenville should be determined by looking at the USDA zone info.

Planting Calendar for Common hollyhock

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

You can plant common hollyhock a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant common hollyhock in Warrenville 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 common hollyhock and expect a good harvest is probably September. If you wait any later than that and your common hollyhock may not have a chance to grow to maturity. Starting your common hollyhock 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 Warrenville. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Warrenville is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Warrenville you get a frost after April 15 be ready to protect your common hollyhock if you have a surprise late frost.

USDA Zone Info for Warrenville

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 Warrenville

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