One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Rancho Santa Margarita it's possible to figure out when you can plant delphinium.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since delphinium are barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant delphinium 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 delphinium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. If you are starting your delphinium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Rancho Santa Margarita. You can expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Rancho Santa Margarita is just an average and the actual date of last frost will vary from year to year. Half of the time in Rancho Santa Margarita last frost occurs after January 31 so always be ready to protect your delphinium if you have a 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.