When to Plant Geranium in San Ramon, CA

One of the first steps you take when you are making a decision about 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 San Ramon should be reviewed to figure out when it's possible to plant geranium.


Planting Calendar for Geranium

Frost tolerance for geranium: Not tolerant of frost.
When to plant: After the last frost.

Geranium are not cold tolerant which tells us that you really should wait until it warms up after all chance of frost has passed before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant geranium
Possibly ok, but a risky time to plant geranium
Probably not a good time to plant geranium

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

The last month that you can plant geranium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your geranium may not have a chance to grow to maturity. If you are starting your geranium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Ramon. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for San Ramon may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in San Ramon last frost occurs after February 15 be ready to protect your geranium in the event of a late frost.

USDA Zone Info for San Ramon

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 Low25°F
Highest Expected Low30°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 San Ramon

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