Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of figuring out when it's a good idea to plant geranium is to consult the USDA zone info for Atherton.

Planting Calendar for Geranium

Frost tolerance for geranium:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Geranium require warm weather which means that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant geranium in Atherton 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. Any later than that and 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 little bit earlier.

Last Frost Date

In Atherton the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Atherton is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Atherton last frost occurs after February 15 be ready to cover your geranium in the event of a surprise late frost.

USDA Zone Info for Atherton

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 Atherton

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