One of the best tools that you have as gardeners to help us figure out 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 best time to plant hollyhocks in Ann Arbor should be estimated 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 start planting them earlier than more sensitive plants.

The earliest that you can plant hollyhocks in Ann Arbor 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 really do well. 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 Ann Arbor. In the coldest months of winter you should expect an average low temperature of -10°F.

Remember that USDA zone info for Ann Arbor is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Ann Arbor it frosts late in the year after April 15 so just be sure to be ready to cover your hollyhocks in the event of a surprise late frost.

USDA Zone Info for Ann Arbor

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ann Arbor

You may be interested in your other planting guides for Ann Arbor.