One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

In Palo Alto you can figure out when to plant celery by looking at the USDA zone info.

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 are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant celery in Palo Alto 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 celery and expect a good harvest is probably September. You probably don't want to wait any later than that or else your celery may not have a chance to really do well. If you are starting your celery indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Palo Alto the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Palo Alto and it is different every year. Half of the time in Palo Alto you get a frost after February 15 so just be sure to be ready to protect your celery in the event of a surprise late frost.

USDA Zone Info for Palo Alto

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

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

Plants to Grow in Palo Alto

You may be interested in your other planting guides for Palo Alto.