One of the first steps you take when you are estimating 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.

In Honolulu you can estimate when it's the best time to plant alternanthera by looking at the USDA zone info.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Alternanthera do not do well in cold weather which tells us that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant alternanthera 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 alternanthera and expect a good harvest is probably November. You probably don't want to wait any later than that or else your alternanthera may not have a chance to fully mature. If you are starting your alternanthera indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Honolulu may not be accurate from year to year 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 protect your alternanthera if you have 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.