One of the best tools that you have as gardeners to help us figure out 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 getting a good idea when it's the best time to plant celery is to examine the USDA zone info for Portland.

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 mild cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant celery in Portland 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. You probably don't want to wait any later than that or else your celery may not have a chance to fully mature. Starting your celery indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Portland is just an average and the actual date of last frost is different every year. Half of the time in Portland last frost occurs after April 15 so make sure that you are ready to cover your celery in the event of one of those late frosts.

USDA Zone Info for Portland

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 Portland

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