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.

You should be able to determine when it's the best time to plant celeriac by using the USDA zone info for Williston.

Planting Calendar for Celeriac

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

Since celeriac do well in moderate cold you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant celeriac in Williston is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant celeriac and expect a good harvest is probably August. Any later than that and your celeriac may not have a chance to really do well. If you are starting your celeriac indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Williston. In the coldest months of winter you should expect an average low temperature of -30°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Williston and it changes from year to year. Half of the time in Williston there is a last frost after May 15 so just be sure to be ready to cover your celeriac in the event of a surprise late frost.

USDA Zone Info for Williston

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Williston

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