One of the best tools that you have as gardeners to help us figure out 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.

By using the USDA zone info for Pasadena you should be able to figure out when to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant dahlias until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias in Pasadena 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 dahlias and expect a good harvest is probably September. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. Starting your dahlias indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Pasadena the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Pasadena and it will vary from year to year. Half of the time in Pasadena there is a last frost after January 31 so make sure that you are prepared to protect your dahlias in the event of a surprise late frost.

USDA Zone Info for Pasadena

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Pasadena

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