One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's possible to plant rhubarb is to refer to the USDA zone info for Sunnyvale.

Planting Calendar for Rhubarb

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

Rhubarb do well in moderate cold which tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant rhubarb in Sunnyvale 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 fully mature. Starting your rhubarb indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Sunnyvale. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Sunnyvale may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Sunnyvale last frost occurs after February 15 so make sure that you are prepared to cover your rhubarb in the event of a late frost.

USDA Zone Info for Sunnyvale

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 Sunnyvale

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