When to plant watermelons in San Marino: 16 May – 2 September

In San Marino, watermelon: sow for seedlings from 28 March to 5 August; plant into a greenhouse from 25 April to 2 September; plant out into open ground from 16 May to 2 September. For plants and seeds, the places nearby include I Sette Punti Verdi (garden centre, 7 km) and Cooperativa Terremerse Corpolò e Centro Cereali (farm supply, 10 km); addresses and opening hours are below.

Watermelon in San Marino: soil, season and weather

In San Marino the soil, not frost, sets the date: the last frost is over around 9 February, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 16 May, 96 days later.

Last spring frost	9 February
Top 7 cm of soil at 18 °C	16 May, 96 days after the last frost
Into an unheated greenhouse	25 April – 2 September; April outside: 8.4 °C at night, 17.6 °C by day; card 18–35 °C
First autumn frost	12 December, 210 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	14 July – 31 October
Days left for picking	151
Daylight	13:34 on 18 April, 14:46 on 16 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, July, has 7 rainy days

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

Watermelon in San Marino: care after planting

Planted on 16 May: in the first weeks water every 5 days.

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

16 May — 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 San Marino during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 30 °C. Months that stay below 18 °C even by day on average: November (14.2 °C) and December (10.4 °C). Nights average below 18 °C in May, June and September–December (3.4–17.7 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	21.6	12.5	98	13	14:44
June	27.7	17.7	57	8	15:27
July	30	19.9	46	7	15:10
August	29.5	19.8	62	8	14:02
September	25	15.9	98	9	12:34
October	20.3	12	83	9	11:04
November	14.2	7.2	103	12	9:40
December	10.4	3.4	67	10	8:55

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around San Marino, Ancona is 6 days earlier and Arezzo 24 days later.

City	Distance	Date	Difference
Rimini	16 km	16 May – 2 September	same day
Ravenna	56 km	15 May – 2 September	1 day earlier
Arezzo	70 km	9 June – 12 August	24 days later
Perugia	92 km	29 May – 16 August	13 days later
Ancona	93 km	10 May – 1 September	6 days earlier
Florence	97 km	28 May – 18 August	12 days later

Where to buy watermelon plants and seeds near San Marino

Buy plants ready to set out from 16 May to 2 September (from 25 April to 2 September for an unheated greenhouse); seed for raising your own is sown from 28 March to 5 August. Within 15 km of San Marino OpenStreetMap lists 8 garden centres, 5 farm-supply shops, 1 plant nursery, 1 market and 4 farm shops (collected 20 October 2026).

I Sette Punti Verdi — garden centre
Via Casale 330 · 7 km
Ghiselli Patrick — garden centre
Via Valdazze 25 · 12 km
Soc. Agr. Calicchio — plant nursery
Via Camerano 17 · 12 km · vivaicalicchio.it
Cooperativa Terremerse Corpolò e Centro Cereali — farm supply
Via Anacleto Ricci 3, 47923 Rimini · 10 km · terremerse.it

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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