Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant sunflowers in Vallejo by checking out the USDA zone info.

Planting Calendar for Sunflowers

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

You can not plant sunflowers until after the last frost has passed because they require warm weather.

The earliest that you can plant sunflowers in Vallejo 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 sunflowers and expect a good harvest is probably September. If you wait any later than that and your sunflowers may not have a chance to fully mature. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Vallejo. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Vallejo is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Vallejo you get a frost after February 15 so just be sure to be ready to protect your sunflowers in the event of a late frost.

USDA Zone Info for Vallejo

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 Vallejo

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