One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Penns Grove you should be able to estimate when it's the best time 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 bit earlier in the year than more sensitive plants.

The earliest that you can plant common hollyhock in Penns Grove 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. You can get started a few weeks earlier by starting your common hollyhock indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Penns Grove. In the coldest months of winter you should expect an average low temperature of 5°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Penns Grove and it can change quite a bit from year to year. Since half of the time in Penns Grove last frost occurs after April 15 be ready to protect your common hollyhock in the event of a late frost.

USDA Zone Info for Penns Grove

Here is the info for USDA Zone 7b.

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

Plants to Grow in Penns Grove

You may be interested in your other planting guides for Penns Grove.