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.

By checking out the USDA zone info for Princeton you should be able to figure out 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.

Since common hollyhock are moderately cold tolerant you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock in Princeton 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. Any later than that and your common hollyhock may not have a chance to fully mature. You can get started a little bit earlier by starting your common hollyhock indoors.

Last Frost Date

In Princeton the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Always keep in mind that USDA zone info for Princeton is just an average and the actual date of last frost will vary from year to year. Half of the time in Princeton you get surprised by a frost after April 15 so make sure that you are ready to protect your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Princeton

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