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When to Plant Delphinium in Fullerton, CA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of estimating when to plant delphinium is to use the USDA zone info for Fullerton.


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 plant them slightly earlier than other plants that might not handle 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 Fullerton 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 little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Fullerton. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that USDA zone info for Fullerton may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Fullerton you get surprised by a frost after January 31 so make sure that you are prepared to protect your delphinium in the event of one of those late frosts.

USDA Zone Info for Fullerton

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 Fullerton

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