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.

One way of estimating when it's possible to plant celery is to look at the USDA zone info for Portola Valley.

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 means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant celery in Portola Valley 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. Starting your celery indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Portola Valley. You can expect an average low temperature of 30°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portola Valley and it changes from year to year. Since half of the time in Portola Valley last frost occurs after January 31 be ready to cover your celery if you have one of those late frosts.

USDA Zone Info for Portola Valley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°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 35°F.

Plants to Grow in Portola Valley

You may be interested in your other planting guides for Portola Valley.