Before planting it is a good idea to find your USDA Zone info to determine 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.

The earliest that you can plant hollyhocks in Columbus can be determined by reviewing the USDA zone info.

Planting Calendar for Hollyhocks

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

Hollyhocks can survive in a little bit of cold which tells us that you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

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. Any later than that and your hollyhocks may not have a chance to fully mature. You can get started a little bit earlier by starting your hollyhocks indoors.

Last Frost Date

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

Since the USDA zone info for Columbus is not always accurate the actual date of last frost is different every year. Half of the time in Columbus there is a last frost after April 15 so make sure that you are ready to cover your hollyhocks in the event of a late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 5b.

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

Plants to Grow in Columbus

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