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.

A way of figuring out when it's the best time to plant celeriac is to refer to the USDA zone info for Harrisburg.

Planting Calendar for Celeriac

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

Celeriac are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant celeriac in Harrisburg 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 celeriac and expect a good harvest is probably September. If you wait any later than that and your celeriac may not have a chance to really do well. You can get started a couple of weeks earlier by starting your celeriac indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Harrisburg. You can expect an average low temperature of 0°F in the coldest months of winter.

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

USDA Zone Info for Harrisburg

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 Harrisburg

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