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When to plant in Key Largo, FL

USDA Zone 11a

Everything below — frost dates, hardiness zone, and what to plant when in Key Largo, Florida — is derived from the closest NOAA station with complete climate normals.

With only about -3 frost-free days, Key Largo has a short season — start heat-lovers indoors early, favor quick-maturing varieties, and use row cover to stretch both ends. These dates come from a station roughly 35 km away, the closest with full normals; terrain around Key Largo (elevation, water, pavement) can move your real frost dates a few days either way. Zone 11a is warm enough that Key Largo can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · ROYAL PALM RS · 34.6 km
Last spring frost
January 20
50% chance · 32°F
First fall frost
January 17
50% chance · 32°F
Growing season
-3 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Key LargoA year-band from January to December for Key Largo: Key Largo is effectively frost-free at 32°F — no distinct frost season.
Key Largo is effectively frost-free at 32°F — no distinct frost season.

Frost probability

ROYAL PALM RS · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Key Largo’s own odds, recorded at ROYAL PALM RS.

Frost-probability curves for Key LargoProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 20 and the first fall frost around January 17, where a 32°F freeze is rare enough that there is effectively no distinct frost season.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMar 3Jan 28Jan 1Dec 25Jan 16Feb 21
32°FFeb 18Jan 20Jan 1Dec 29Jan 17Feb 17

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19

Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.

Add the next planting windows to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Key Largo, drawn to the day from the local frost dates. The dashed line is today.

Key Largo planting FAQ

When is the last spring frost in Key Largo, FL?

On average, the last spring frost in Key Largo is around January 20 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in Key Largo, FL?

Expect Key Largo's first fall frost near January 17 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Key Largo in?

Key Largo is in USDA hardiness zone 11a. In zone 11a, winters are mild — many tender perennials overwinter here.

How long is the growing season in Key Largo?

There are roughly -3 frost-free days in Key Largo (a short growing season), running from the average last frost around January 20 to the first fall frost near January 17.

When should I plant tomatoes in Key Largo?

In Key Largo, start tomato seeds indoors around November 25–December 9, then transplant seedlings outdoors around January 27 once the danger of frost has passed.

Planting reminders

Never miss a window in Key Largo

An email when it’s time to start seeds, transplant, and sow — timed to Key Largo’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at ROYAL PALM RS, 35 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Key Largo, FL — Frost Dates & Zone 11a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00087760. Retrieved from https://blissgarden.com/florida/key-largo.