When to Plant Delphinium in Hayward, CA

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

One way of figuring out when it's possible to plant delphinium is to refer to the USDA zone info for Hayward.


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 just a tiny bit earlier in the year because they are barely cold tolerant.

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 Hayward 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. Any later than that and your delphinium may not have a chance to fully mature. Starting your delphinium indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Hayward the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Hayward and it changes from year to year. Half of the time in Hayward you get a frost after January 31 so always be ready to protect your delphinium if you have a late frost.

USDA Zone Info for Hayward

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 Hayward

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