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.

The USDA zone info for Vallejo can be reviewed to estimate when it's the best time to plant dahlias.

Planting Calendar for Dahlias

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

You really shouldn't plant dahlias until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias 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 dahlias and expect a good harvest is probably September. Any later than that and your dahlias may not have a chance to really do well. You can get started a couple of weeks earlier by starting your dahlias indoors.

Last Frost Date

On average the last frost is on February 15 in Vallejo. You should expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Vallejo and it will vary from year to year. Half of the time in Vallejo there is a last frost after February 15 so be sure to be ready to protect your dahlias if you have one of those late frosts.

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.