When to plant watermelons in Santa Fe: from 20 September

In Santa Fe, watermelon: sow for seedlings from 2 August; plant into a greenhouse from 30 August; plant out into open ground from 20 September. There is no autumn frost here, so the frost dates set no end to the window.

Watermelon in Santa Fe: soil, season and weather

In Santa Fe the soil, not frost, sets the date: the last frost is over around 1 July, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 20 September, 81 days later. Santa Fe has no autumn frost in the median year, so frost does not end the season.

Last spring frost	1 July
Top 7 cm of soil at 18 °C	20 September, 81 days after the last frost
Into an unheated greenhouse	from 30 August; August outside: 9.9 °C at night, 19.5 °C by day; card 18–35 °C
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	from 18 November
Daylight	11:10 on 23 August, 12:02 on 20 September
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 4 rainy days

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

Watermelon in Santa Fe: care after planting

Planted on 20 September: in the first weeks water every 5 days.

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

20 September — 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 Santa Fe during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 31 °C. Nights average below 18 °C in September (12.2 °C), October (14.8 °C) and November (17.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
September	22.4	12.2	43	4	11:52
October	25	14.8	80	7	12:50
November	27.9	17.8	95	8	13:43
December	29.8	20.1	99	8	14:12
January	31	22	115	8	13:59
February	30.1	21.2	113	8	13:12

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Santa Fe, Salto is 29 days earlier and Córdoba 11 days later.

City	Distance	Date	Difference
Paraná	19 km	from 10 September	10 days earlier
Rosario	145 km	29 September – 5 March	9 days later
Paysandú	259 km	21 September – 17 March	1 day later
Salto	262 km	from 22 August	29 days earlier
Córdoba	330 km	1 October – 5 March	11 days later
Río Cuarto	379 km	29 September – 4 March	9 days later

Where to buy watermelon plants and seeds near Santa Fe

Buy plants ready to set out from 20 September (from 30 August for an unheated greenhouse); seed for raising your own is sown from 2 August. Within 15 km of Santa Fe OpenStreetMap lists 1 garden centre, 1 farm-supply shop, 3 markets and 188 farm shops (collected 27 October 2026).

Red Surcos — farm supply
1 km
Fanny — market
7 km
Deposito N°68 — farm shop
10 km
Deposito N°67 — farm shop
10 km

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