One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 Pasadena can be looked at to estimate when it's possible 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 can not plant dahlias until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant dahlias in Pasadena 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. If you wait any later than that and your dahlias may not have a chance to fully mature. Starting your dahlias indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Pasadena. In the coldest months of winter you should expect an average low temperature of 20°F.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Pasadena and it changes from year to year. Half of the time in Pasadena it frosts late in the year after February 15 so make sure that you are ready to cover your dahlias in the event of one of those late frosts.

USDA Zone Info for Pasadena

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Pasadena

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