Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Honolulu can be read to estimate when to plant welsh onion.

Planting Calendar for Welsh onion

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

Welsh onion tend to make it in some cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

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

Last Frost Date

In Honolulu it never frosts. In the coldest months of winter you should expect an average low temperature of 50°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Honolulu and it changes from year to year. Since it never frosts in Honolulu you do not have to be ready to cover your welsh onion 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.