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When to plant in Port St. John, FL

USDA Zone 10a

Port St. John, Florida frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

Port St. John's growing season is short at roughly -12 days, so succession planting is limited; lean on transplants over direct sowing for anything slow to mature. These dates come from a station roughly 17 km away, the closest with full normals; terrain around Port St. John (elevation, water, pavement) can move your real frost dates a few days either way. Zone 10a is warm enough that Port St. John can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · TITUSVILLE · 16.5 km
Last spring frost
January 25
50% chance · 32°F
First fall frost
January 13
50% chance · 32°F
Growing season
-12 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Port St. JohnA year-band from January to December for Port St. John: Port St. John is effectively frost-free at 32°F — no distinct frost season.
Port St. John is effectively frost-free at 32°F — no distinct frost season.

The average first fall frost in Port St. John is now 8 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

TITUSVILLE · 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 Port St. John’s own odds, recorded at TITUSVILLE.

Frost-probability curves for Port St. JohnProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around January 25 and the first fall frost around January 13, 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 7Feb 3Jan 5Dec 9Jan 5Feb 4
32°FFeb 24Jan 25Dec 31Dec 23Jan 13Feb 10
28°FFeb 8Jan 22Dec 27Dec 25Jan 16Feb 7

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 Port St. John, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 29 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

TITUSVILLE
Primary
17 km · 5 m elevation
SPRING
Jan 25
FALL
Jan 13
TITUSVILLE 7 E
19 km · 1 m elevation
SPRING
Jan 29
FALL
Jan 16
SCOTTSMOOR 2.5 SSW
29 km · 13 m elevation
SPRING
Feb 10
FALL
Jan 8

Port St. John planting FAQ

When is the last spring frost in Port St. John, FL?

Plan for the last spring frost in Port St. John around January 25 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Port St. John, FL?

In Port St. John, the first 32°F freeze of fall lands around January 13 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Port St. John in?

Port St. John is in USDA hardiness zone 10a. In zone 10a, winters are mild — many tender perennials overwinter here.

How long is the growing season in Port St. John?

There are roughly -12 frost-free days in Port St. John (a short growing season), running from the average last frost around January 25 to the first fall frost near January 13.

When should I plant tomatoes in Port St. John?

In Port St. John, start tomato seeds indoors around November 30–December 14, then transplant seedlings outdoors around February 1 once the danger of frost has passed.

Planting reminders

Never miss a window in Port St. John

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

Nearby cities

8 within reach

Frost dates recorded at TITUSVILLE, 17 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 Port St. John, FL — Frost Dates & Zone 10a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00088942. Retrieved from https://blissgarden.com/florida/port-st-john.