Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 Harvard can be read to figure out when to plant celery.

Planting Calendar for Celery

Frost tolerance for celery:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Celery do ok in moderate cold which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant celery in Harvard 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 celery and expect a good harvest is probably August. If you wait any later than that and your celery may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your celery indoors.

Last Frost Date

The average date of last frost is April 15 in Harvard. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Harvard may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Harvard it frosts late in the year after April 15 be ready to cover your celery if you have one of those late frosts.

USDA Zone Info for Harvard

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 Harvard

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