The USDA Zone info is a great tool for gardeners to help us estimate your gardening 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 Orange can be used to estimate when to plant dahlia.

Planting Calendar for Dahlia

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

It's probably a bad idea to plant dahlia until after the last frost because they are not cold tolerant.

The earliest that you can plant dahlia in Orange is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to really do well. If you are starting your dahlia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Orange. In the coldest months of winter you should expect an average low temperature of 0°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Orange and it will vary from year to year. Half of the time in Orange you get surprised by a frost after April 15 so always be ready to protect your dahlia in the event of a surprise late frost.

USDA Zone Info for Orange

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Orange

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