One of the first steps you take when you are figuring out 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.

The USDA zone info for Petaluma should be used to determine when you can plant black radish.

Planting Calendar for Black radish

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

Black radish are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than plants that are more sensitive to the cold.

The earliest that you can plant black radish in Petaluma 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 black radish and expect a good harvest is probably October. If you wait any later than that and your black radish may not have a chance to grow to maturity. Starting your black radish 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 Petaluma. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Petaluma may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Petaluma you get a frost after February 15 be ready to protect your black radish if you have a late frost.

USDA Zone Info for Petaluma

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 Petaluma

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