One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Irvine you can estimate when you can plant radishes by using the USDA zone info.

Planting Calendar for Radishes

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

Radishes can survive in pretty solid cold which tells us that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant radishes in Irvine 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. Any later than that and your radishes may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your radishes indoors.

Last Frost Date

On average the last frost is on January 31 in Irvine. You should expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Irvine and it changes from year to year. Half of the time in Irvine last frost occurs after January 31 so just be sure to be ready to protect your radishes in the event of a surprise late frost.

USDA Zone Info for Irvine

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Irvine

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