The USDA Zone info is a great tool for gardeners to help us determine 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.

It's a good idea to figure out when to plant regal geranium by referring to the USDA zone info for San Mateo.

Planting Calendar for Regal Geranium

Frost tolerance for regal geranium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since regal geranium are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant regal geranium in San Mateo is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant regal geranium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your regal geranium may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your regal geranium indoors.

Last Frost Date

On average all chance of frost has passed is on January 31 in San Mateo. It might get as low as 30°F during the coldest months of winter.

It's important to remember that USDA zone info for San Mateo may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in San Mateo you get a frost after January 31 so always be ready to protect your regal geranium in the event of 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.