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

The earliest that you can plant common hollyhock in Glassboro should be estimated by referring to 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.

Common hollyhock are moderately cold tolerant which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant common hollyhock in Glassboro 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 really do well. If you are starting your common hollyhock indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Glassboro. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Glassboro is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Glassboro it frosts late in the year after April 15 be ready to protect your common hollyhock if you have a surprise late frost.

USDA Zone Info for Glassboro

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Glassboro

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