Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when to plant common hollyhock is to consult the USDA zone info for Ypsilanti.

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 one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant common hollyhock in Ypsilanti 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. You probably don't want to wait any later than that or else your common hollyhock may not have a chance to fully mature. If you are starting your common hollyhock indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Ypsilanti. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ypsilanti and it changes from year to year. Half of the time in Ypsilanti it frosts late in the year after April 15 so just be sure to be ready to cover your common hollyhock in the event of a late frost.

USDA Zone Info for Ypsilanti

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 Ypsilanti

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