When to Plant Onions in Key West, FL

One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant onions in Key West should be determined by reviewing the USDA zone info.


Planting Calendar for Onions

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

You can plant onions quite a bit earlier in the year because they do well in cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Key West 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 onions and expect a good harvest is probably November. You probably don't want to wait any later than that or else your onions may not have a chance to fully mature. Starting your onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Key West it never frosts. In the coldest months of winter you should expect an average low temperature of 45°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 Key West and it is different every year. Since it never frosts in Key West you do not have to be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Key West

Here is the info for USDA Zone 11b.

Average Date of Last Frost (spring)Never
Average Date of First Frost (fall)Never
Lowest Expected Low45°F
Highest Expected Low50°F

This means that on a really cold year, the coldest it will get is 45°F. On most years you should be prepared to experience lows near 50°F.

Plants to Grow in Key West

You may be interested in your other planting guides for Key West.