When to plant watermelons in Santa Maria: 14 August – 3 March

In Santa Maria, watermelon: sow for seedlings from 26 June to 4 February; plant into a greenhouse from 24 July to 3 March; plant out into open ground from 14 August to 3 March. For plants and seeds, the places nearby include Agropecuária Fronteira (farm supply, 6 km); addresses and opening hours are below.

Watermelon in Santa Maria: soil, season and weather

In Santa Maria the soil, not frost, sets the date: the last frost is over around 16 July, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 14 August, 29 days later.

Last spring frost	16 July
Top 7 cm of soil at 18 °C	14 August, 29 days after the last frost
Into an unheated greenhouse	24 July – 3 March; July outside: 9.8 °C at night, 19.3 °C by day; card 18–35 °C
First autumn frost	12 June, 303 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	12 October – 1 May
Days left for picking	244
Daylight	10:26 on 17 July, 11:00 on 14 August
Watering outdoors when fruiting (card)	every 5 days; the driest month, February, has 10 rainy days

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

Watermelon in Santa Maria: care after planting

Planted on 14 August: in the first weeks water every 5 days.

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

14 August — 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 Maria during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 30.6 °C. Nights average below 18 °C in April–June and August–November (10.5–16.5 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
August	20.8	10.6	127	9	11:02
September	22.6	13	193	13	11:53
October	24.5	14.6	173	12	12:46
November	27.3	16.5	132	10	13:36
December	29.8	19	110	11	14:02
January	30.6	20.6	113	12	13:51
February	30.1	20.1	91	10	13:07
March	28.3	18.7	138	10	12:18
April	25.2	16.1	131	9	11:23
May	20.8	12.5	196	12	10:39
June	19.2	10.5	141	9	10:15

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Santa Maria, Posadas is 20 days earlier and Tacuarembó 61 days later.

City	Distance	Date	Difference
Passo Fundo	209 km	8 September – 8 March	25 days later
Rivera	214 km	28 September – 29 February	45 days later
Caxias do Sul	261 km	1 September – 7 March	18 days later
Tacuarembó	307 km	14 October – 4 March	61 days later
Chapecó	310 km	12 September – 14 March	29 days later
Posadas	328 km	from 25 July	20 days earlier

Where to buy watermelon plants and seeds near Santa Maria

Buy plants ready to set out from 14 August to 3 March (from 24 July to 3 March for an unheated greenhouse); seed for raising your own is sown from 26 June to 4 February. Within 15 km of Santa Maria OpenStreetMap lists 1 garden centre, 4 farm-supply shops, 1 plant nursery and 5 markets (collected 27 October 2026).

Agropecuária Fronteira — farm supply
Rua Evaristo Menezes dos Santos 55, 97061-042 · 6 km
PoliFeira do Agricultor — market
Rua Barão do Triunfo, Santa Maria · Tue 12:00–17:30 · 1 km
Feira Ana Primavesi — market
Avenida Roraima, Santa Maria · Wed 10:00–12:30 · 10 km
Feira de Produtos Coloniais e Hortifrútis — market
Avenida Roraima · Wed, Sat 06:00–12:00 · 10 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.

Questions