One of the best tools that you have as gardeners to help us estimate 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 way of figuring out when it's the best time to plant radishes is to refer to the USDA zone info for Santa Rosa.

Planting Calendar for Radishes

Frost tolerance for radishes:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Radishes are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than other frost tender plants.

The earliest that you can plant radishes in Santa Rosa 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 radishes and expect a good harvest is probably October. You probably don't want to wait any later than that or else your radishes may not have a chance to fully mature. Starting your radishes 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 Santa Rosa. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Santa Rosa is not always accurate the actual date of last frost changes from year to year. Half of the time in Santa Rosa it frosts late in the year after February 15 so just be sure to be ready to protect your radishes if you have one of those late frosts.

USDA Zone Info for Santa Rosa

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 Santa Rosa

You may be interested in your other planting guides for Santa Rosa.