One of the first steps you take when you are determining 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.

In Palo Alto you can estimate when it's possible to plant rhubarb by referring to the USDA zone info.

Planting Calendar for Rhubarb

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

Rhubarb can survive in a little bit of cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant rhubarb in Palo Alto is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant rhubarb and expect a good harvest is probably October. If you wait any later than that and your rhubarb may not have a chance to really do well. Starting your rhubarb indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Palo Alto. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Palo Alto may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Palo Alto there is a last frost after February 15 so be sure to be ready to cover your rhubarb if you have 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.