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 USDA zone info for Posen can be looked at to determine when to plant common hollyhock.

Planting Calendar for Common hollyhock

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

Common hollyhock are one of those plants that can tolerate a little bit of cold weather which means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant common hollyhock in Posen 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 really do well. Starting your common hollyhock indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Posen. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Posen is an average the actual date of last frost changes from year to year. Half of the time in Posen last frost occurs after April 15 so make sure that you are ready to cover your common hollyhock in the event of one of those late frosts.

USDA Zone Info for Posen

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 Posen

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