The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Union you should be able to determine when it's the best time to plant celeriac.

Planting Calendar for Celeriac

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

Celeriac do well in moderate cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant celeriac in Union 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. You probably don't want to wait any later than that or else your celeriac may not have a chance to fully mature. You can get started a little bit earlier by starting your celeriac indoors.

Last Frost Date

In Union the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Union and it will vary from year to year. Half of the time in Union there is a last frost after April 15 so be sure to be ready to protect your celeriac if you have a surprise late frost.

USDA Zone Info for Union

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Union

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