The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Rancho Santa Margarita should be reviewed to figure out when it's a good idea to plant dahlias.

Planting Calendar for Dahlias

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

It's probably not a good idea to plant dahlias until after the last frost because they require warm weather.

The earliest that you can plant dahlias in Rancho Santa Margarita 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 really do well. Starting your dahlias indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Rancho Santa Margarita. In the coldest months of winter you should expect an average low temperature of 30°F.

Since the USDA zone info for Rancho Santa Margarita may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Rancho Santa Margarita last frost occurs after January 31 so make sure that you are prepared to cover your dahlias if you have a surprise late frost.

USDA Zone Info for Rancho Santa Margarita

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 Rancho Santa Margarita

You may be interested in your other planting guides for Rancho Santa Margarita.