One of the first steps you take when you are determining 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.

It's possible to determine when it's the best time to plant geranium by using the USDA zone info for California.

Planting Calendar for Geranium

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

Geranium are not cold tolerant which tells us that you need to 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 California is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant geranium and expect a good harvest is probably August. 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

In California the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for California and it is different every year. Since half of the time in California it frosts late in the year after April 15 be ready to cover your geranium if you have one of those late frosts.

USDA Zone Info for California

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in California

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