The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to figure out when you can plant rhubarb by looking at the USDA zone info for Corona.

Planting Calendar for Rhubarb

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

Rhubarb do ok in a little bit of cold which means that you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant rhubarb in Corona 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. Any later than that and your rhubarb may not have a chance to grow to maturity. Starting your rhubarb indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Corona. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Corona may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Corona you get surprised by a frost after February 15 so always be ready to protect your rhubarb if you have one of those late frosts.

USDA Zone Info for Corona

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 Corona

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