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

By using the USDA zone info for Whittier it's a good idea to estimate when you can plant dahlia.

Planting Calendar for Dahlia

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

You really shouldn't plant dahlia until after all chance of frost has passed because they require warm weather.

The earliest that you can plant dahlia in Whittier 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 dahlia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your dahlia may not have a chance to fully mature. If you are starting your dahlia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Whittier. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Whittier is just an average the actual date of last frost is different every year. Since half of the time in Whittier you get surprised by a frost after January 31 be ready to cover your dahlia in the event of a surprise late frost.

USDA Zone Info for Whittier

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 Whittier

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