Before planting it is a good idea to find your USDA Zone info to estimate 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.

The first opportunity to plant sunflowers in Zone 10b should be determined by referring to the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since sunflowers do not do well in cold weather you really should wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant sunflowers in Zone 10b 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 sunflowers and expect a good harvest is probably September. Any later than that and your sunflowers may not have a chance to really do well. If you are starting your sunflowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Zone 10b. You can expect an average low temperature of 35°F in the coldest months of winter.

Since the USDA zone info for Zone 10b is not always accurate the actual date of last frost is different every year. Half of the time in Zone 10b you get a frost after January 31 so just be sure to be ready to protect your sunflowers in the event of one of those late frosts.

USDA Zone Info for Zone 10b

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Zone 10b

You may be interested in your other planting guides for Zone 10b.