🧅 When to Plant Onions in Zone 11

Zone 11 is frost-free (Miami and the Keys, Hawaiʻi coasts) — plant onions through the coolest months, typically October to March.

No frost windows apply in zone 11. Grow onions through the coolest months (typically October–March); it bolts or fades once real heat arrives.
Zone 11 frost window
Frost-free
Miami and the Keys, Hawaiʻi coasts
Spacing
4″ / 12″
plants / rows
Maturity
90–110 days
from transplant

Growing onions in zone 11

Bulbing is triggered by day length: long-day varieties for the North, short-day for the South, intermediate in between — the wrong type simply won’t bulb. Sets are easiest; transplants give bigger bulbs.

Zone 11 covers miami and the Keys, Hawaiʻi coasts — frost-free — plant warm-season crops most of the year; cool crops in the mildest months.

Make it local

These windows use zone 11's typical frost dates. For windows computed from your frost dates, run the ZIP code frost lookup and open the planting calendar — it remembers your city. The seed starting scheduler turns the whole seed rack into one printable, date-sorted list.

Frequently asked questions

When should I plant onions in zone 11?

Zone 11 is frost-free, so timing flips from frost-avoidance to heat management: plant onions through the coolest months, typically October to March. Summer heat, not winter cold, is what ends this crop here.

Does onions grow well in zone 11?

Yes, in the right months. Onions is a cool-season crop, so grow it through zone 11's mildest stretch and expect it to bolt or fade as serious heat builds.