One of the best tools that you have as gardeners to help us figure out 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.

A common way of figuring out when it's possible to plant hollyhocks is to look at the USDA zone info for Columbus.

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 start planting them earlier than other frost tender plants.

The earliest that you can plant hollyhocks in Columbus 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 really do well. You can get started a little bit earlier by starting your hollyhocks indoors.

Last Frost Date

The average date of last frost is March 15 in Columbus. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Columbus is just an average the actual date of last frost changes from year to year. Half of the time in Columbus you get surprised by a frost after March 15 so just be sure to be ready to cover your hollyhocks in the event of one of those late frosts.

USDA Zone Info for Columbus

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Columbus

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