The USDA Zone info is a great tool for gardeners to help us figure out your gardening 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 making a decision about when it's a good idea to plant common hollyhock is to examine the USDA zone info for Collingswood.

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 tend to make it in mild cold which tells us that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant common hollyhock in Collingswood 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 grow to maturity. You can get started a couple of weeks earlier by starting your common hollyhock indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Collingswood. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Collingswood is an average the actual date of last frost changes from year to year. Half of the time in Collingswood you get surprised by a frost after April 15 so just be sure to be ready to cover your common hollyhock in the event of a surprise late frost.

USDA Zone Info for Collingswood

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 Collingswood

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