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.

One way of making a decision about when it's possible to plant delphinium is to look at the USDA zone info for Arvin.

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.

Delphinium are barely cold tolerant which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant delphinium in Arvin 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 fully mature. You can get started a little bit earlier by starting your delphinium indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Arvin. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Arvin is not always accurate the actual date of last frost changes from year to year. Since half of the time in Arvin there is a last frost after February 15 be ready to cover your delphinium if you have one of those late frosts.

USDA Zone Info for Arvin

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 Arvin

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