Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when to plant hollyhocks by checking out the USDA zone info for Raritan.

Planting Calendar for Hollyhocks

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

Hollyhocks are moderately cold tolerant which means that you can get them planted earlier than more sensitive plants.

The earliest that you can plant hollyhocks in Raritan 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 hollyhocks and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hollyhocks may not have a chance to fully mature. Starting your hollyhocks indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Raritan. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Raritan is an average the actual date of last frost changes from year to year. Half of the time in Raritan last frost occurs after April 15 so make sure that you are ready to cover your hollyhocks if you have a surprise late frost.

USDA Zone Info for Raritan

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 Raritan

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