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.

You will be able to determine when it's possible to plant rhubarb by using the USDA zone info for Napa.

Planting Calendar for Rhubarb

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

You can plant rhubarb just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant rhubarb in Napa 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. You probably don't want to wait any later than that or else your rhubarb may not have a chance to fully mature. If you are starting your rhubarb indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Napa and it changes from year to year. Since half of the time in Napa you get a frost after February 15 be ready to cover your rhubarb in the event of one of those late frosts.

USDA Zone Info for Napa

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 Napa

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