When to plant watermelons in Rancagua: 6 November – 2 March

In Rancagua, watermelon: sow for seedlings from 18 September to 3 February; plant into a greenhouse from 16 October to 2 March; plant out into open ground from 6 November to 2 March.

Watermelon in Rancagua: soil, season and weather

In Rancagua the soil, not frost, sets the date: the last frost is over around 18 August, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 6 November, 80 days later.

Last spring frost	18 August
Top 7 cm of soil at 18 °C	6 November, 80 days after the last frost
Into an unheated greenhouse	16 October – 2 March; October outside: 8.6 °C at night, 20.9 °C by day; card 18–35 °C
First autumn frost	11 June, 218 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	4 January – 30 April
Days left for picking	159
Daylight	12:42 on 9 October, 13:38 on 6 November
Watering outdoors when fruiting (card)	every 5 days; the driest month, December, has 1 rainy day

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

Watermelon in Rancagua: care after planting

Planted on 6 November: in the first weeks water every 5 days.

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

6 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 Rancagua during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 29.6 °C. Months that stay below 18 °C even by day on average: May (16.7 °C) and June (13.9 °C). Nights average below 18 °C in every month of the season, from 5.1 °C to 14.6 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
November	25.1	10.8	27	3	13:53
December	28.2	12.9	5	1	14:25
January	29.6	14.5	10	1	14:11
February	29.5	14.6	9	2	13:19
March	27.1	12.6	8	1	12:20
April	21.4	9.9	61	4	11:15
May	16.7	7.4	71	8	10:22
June	13.9	5.1	149	9	9:53

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

1 of the nearest cities share Rancagua's date.

City	Distance	Date	Difference
Santiago	80 km	14 October – 8 March	23 days earlier
Curicó	102 km	31 October – 26 February	6 days earlier
Valparaíso	149 km	from 29 October	8 days earlier
Talca	162 km	6 November – 3 March	same day
San Rafael	226 km	22 September – 24 February	45 days earlier
Mendoza	227 km	19 September – 7 March	48 days earlier

Where to buy watermelon plants and seeds near Rancagua

Buy plants ready to set out from 6 November to 2 March (from 16 October to 2 March for an unheated greenhouse); seed for raising your own is sown from 18 September to 3 February. Within 15 km of Rancagua OpenStreetMap lists 8 garden centres, 2 farm-supply shops, 1 plant nursery, 2 markets and 1 farm shop (collected 27 October 2026).

Vivero de Plantas Zúñiga — plant nursery
15 km
Concretagro — farm supply
7 km · concretagro.cl
MyV Martínez y Valdivieso — farm supply
9 km · myv.cl
Copeval — farm shop
5 km · copeval.cl

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.

Questions