One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when you can plant yarrow by checking out the USDA zone info for Honolulu.

Planting Calendar for Yarrow

Frost tolerance for yarrow:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Yarrow do well in quite a bit of cold which tells us that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant yarrow 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 yarrow and expect a good harvest is probably November. Any later than that and your yarrow may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your yarrow indoors.

Last Frost Date

In Honolulu it never frosts. It might get as low as 50°F during the coldest months of winter.

It's important to remember that USDA zone info for Honolulu may not be accurate from year to year and the actual date of last frost will vary from year to year. Since it never frosts in Honolulu you do not have to be ready to protect your yarrow in the event of a 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.