When to plant watermelons in Jacksonville: 11 February – 17 September

In Jacksonville, watermelon: sow for seedlings from 24 December to 20 August; plant into a greenhouse from 21 January to 17 September; plant out into open ground from 11 February to 17 September.

Watermelon in Jacksonville: soil, season and weather

In Jacksonville the soil, not frost, sets the date: the last frost is over around 23 January, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 11 February, 19 days later.

Last spring frost	23 January
Top 7 cm of soil at 18 °C	11 February, 19 days after the last frost
Into an unheated greenhouse	21 January – 17 September; January outside: 8.4 °C at night, 18.2 °C by day; card 18–35 °C
First autumn frost	27 December, 319 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	11 April – 15 November
Days left for picking	260
Daylight	10:23 on 14 January, 11:00 on 11 February
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 7 rainy days

The same dates in Jacksonville hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Jacksonville: care after planting

Planted on 11 February: in the first weeks water every 5 days.

Feeding, by the card’s schedule from that day:

11 February — feed: balanced (NPK)

Pests and diseases of watermelon to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Jacksonville during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 32.5 °C. Nights average below 18 °C in February–April and November, December (10.7–16.1 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
February	21.8	11.5	72	8	11:07
March	24.2	13.3	75	9	11:57
April	26.8	16.1	74	8	12:54
May	30.1	19.7	88	11	13:40
June	31.4	22.9	155	20	14:06
July	32.5	24	158	22	13:56
August	31.5	24	183	25	13:16
September	29.9	22.5	158	17	12:23
October	26.7	18.7	94	11	11:28
November	22.8	13.6	57	7	10:38
December	20	10.7	66	7	10:12

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Jacksonville, Orlando is 17 days earlier and Savannah 14 days later.

City	Distance	Date	Difference
Gainesville	99 km	18 February – 14 September	7 days later
Orlando	201 km	25 January – 15 September	17 days earlier
Savannah	202 km	25 February – 14 September	14 days later
Tallahassee	252 km	24 February – 13 September	13 days later
Tampa	276 km	25 January – 14 September	17 days earlier
St. Petersburg	296 km	from 25 January	17 days earlier

Where to buy watermelon plants and seeds near Jacksonville

Buy plants ready to set out from 11 February to 17 September (from 21 January to 17 September for an unheated greenhouse); seed for raising your own is sown from 24 December to 20 August. Within 15 km of Jacksonville OpenStreetMap lists 4 garden centres, 1 farm-supply shop and 3 markets (collected 20 October 2026).

Front Porch Pickings — market
South McDuff Avenue 1272, 32205 Jacksonville · 5 km · frontporchpickings.com
Riverside Arts Market — market
Sat 10:00–15:00 · 2 km
Cultivate — garden centre
4 km
Walmart Garden Center — garden centre
6 km

Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

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