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.

A common way of figuring out when it's a good idea to plant delphinium is to refer to the USDA zone info for Auburn.

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.

You can plant delphinium a bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant delphinium in Auburn 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. If you wait any later than that and your delphinium may not have a chance to fully mature. 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

The average date of last frost is February 15 in Auburn. In the coldest months of winter you can expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Auburn and it will vary from year to year. Half of the time in Auburn you get a frost after February 15 so always be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Auburn

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Auburn

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