The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for San Mateo you should be able to estimate when it's a good idea to plant radishes.

Planting Calendar for Radishes

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

Since radishes are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant radishes in San Mateo 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. Starting your radishes indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Mateo the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Mateo and it is different every year. Since half of the time in San Mateo it frosts late in the year after January 31 be ready to protect your radishes if you have a surprise late frost.

USDA Zone Info for San Mateo

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 San Mateo

You may be interested in your other planting guides for San Mateo.