One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Alton should be looked at to determine when you can plant celeriac.

Planting Calendar for Celeriac

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

Since celeriac are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant celeriac in Alton 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. 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

In Alton the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Alton is an average and the actual date of last frost is different every year. Half of the time in Alton it frosts late in the year after April 15 so always be ready to cover your celeriac in the event of a late frost.

USDA Zone Info for Alton

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 Alton

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