When can I plant Delphinium in Zone 10a

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

It's a good idea to determine when it's the best time to plant delphinium by reviewing the USDA zone info for Zone 10a.


Planting Calendar for Delphinium

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

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant delphinium
Possibly ok, but a risky time to plant delphinium
Probably not a good time to plant delphinium

The earliest that you can plant delphinium in Zone 10a 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 grow to maturity. If you are starting your delphinium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Zone 10a. In the coldest months of winter we should expect an average low temperature of 30°F.

Just be sure to remember that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 10a and it changes from year to year. Half of the time in Zone 10a there is a last frost after January 31 so make sure that you are prepared to cover your delphinium if we have a surprise late frost.

USDA Zone Info for Zone 10a

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 Low30°F
Highest Expected Low35°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 Zone 10a

You may be interested in our other planting guides for Zone 10a.