One of the best tools that you have as gardeners to help us estimate 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.

The earliest that you can plant delphinium in Honolulu should be estimated by referring to the USDA zone info.

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 do ok in moderate cold which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant delphinium in Honolulu is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably November. 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

In Honolulu it never frosts. You can expect an average low temperature of 50°F in the coldest months of winter.

Keep in mind that USDA zone info for Honolulu is not always accurate and the actual date of last frost changes from year to year. Since it never frosts in Honolulu you do not have to be ready to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Honolulu

Here is the info for USDA Zone 12a.

Average Date of Last Frost (spring)	Never
Average Date of First Frost (fall)	Never
Lowest Expected Low	50°F
Highest Expected Low	55°F

This means that on a really cold year, the coldest it will get is 50°F. On most years you should be prepared to experience lows near 55°F.

Plants to Grow in Honolulu

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