When to plant watermelons in Bahía Blanca: 5 November – 5 March

In Bahía Blanca, watermelon: sow for seedlings from 17 September to 6 February; plant into a greenhouse from 15 October to 5 March; plant out into open ground from 5 November to 5 March. For plants and seeds, the places nearby include Forrajería y vivero Don Bosco (garden centre, 4 km) and Cultivos Bahía Blanca (garden centre, 6 km); addresses and opening hours are below.

Watermelon in Bahía Blanca: soil, season and weather

In Bahía Blanca the soil, not frost, sets the date: the last frost is over around 8 August, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 5 November, 89 days later.

Last spring frost	8 August
Top 7 cm of soil at 18 °C	5 November, 89 days after the last frost
Into an unheated greenhouse	15 October – 5 March; October outside: 11 °C at night, 21.2 °C by day; card 18–35 °C
First autumn frost	14 June, 222 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	3 January – 3 May
Days left for picking	163
Daylight	12:46 on 8 October, 13:53 on 5 November
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 5 rainy days

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

Watermelon in Bahía Blanca: care after planting

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

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

5 November — 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 Bahía Blanca during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 30.4 °C. Months that stay below 18 °C even by day on average: May (16.2 °C) and June (13.4 °C). Nights average below 18 °C in March–June and November, December (5.8–16.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
November	25	14.2	71	7	14:13
December	28.8	16.8	54	6	14:51
January	30.4	19.1	53	6	14:34
February	28.6	18	48	7	13:33
March	25.7	15.8	80	7	12:23
April	21	12.3	63	7	11:06
May	16.2	8.4	46	6	10:03
June	13.4	5.8	29	5	9:28

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Bahía Blanca, Buenos Aires is 29 days earlier and Mar del Plata 7 days later.

City	Distance	Date	Difference
Santa Rosa	293 km	22 October – 3 March	14 days earlier
Mar del Plata	418 km	from 12 November	7 days later
Neuquén	502 km	17 October – 28 February	19 days earlier
Trelew	565 km	22 October – 17 February	14 days earlier
La Plata	571 km	20 October – 7 March	16 days earlier
Buenos Aires	575 km	from 7 October	29 days earlier

Where to buy watermelon plants and seeds near Bahía Blanca

Buy plants ready to set out from 5 November to 5 March (from 15 October to 5 March for an unheated greenhouse); seed for raising your own is sown from 17 September to 6 February. Within 15 km of Bahía Blanca OpenStreetMap lists 9 garden centres and 4 markets (collected 27 October 2026).

Greengrocer's Central Store — market
3 km · mercadocentral.gob.ar
Consorcio Mercado Aguado — market
4 km
Forrajería y vivero Don Bosco — garden centre
Don Bosco 2583, Bahía Blanca · Mon–Sat 09:00–13:30, 16:00–20:00 · 4 km · facebook.com
Cultivos Bahía Blanca — garden centre
Florida 4500, 8000 Bahía Blanca · Mon–Fri 09:00–12:00, 15:00–18:00; Sat 09:00–12:00 · 6 km · cultivosbahiablanca.com.ar

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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