Before planting it is a good idea to find your USDA Zone info to estimate 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.

The first chance to plant astilbe in Honolulu can be estimated by reviewing the USDA zone info.

Planting Calendar for Astilbe

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

You can plant astilbe just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant astilbe 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 astilbe and expect a good harvest is probably November. If you wait any later than that and your astilbe may not have a chance to fully mature. If you are starting your astilbe indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Honolulu and it can change quite a bit from year to year. Since it never frosts in Honolulu you do not have to be ready to protect your astilbe 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.