When to plant watermelons in Aranda de Duero: 31 May – 4 August

In Aranda de Duero, watermelon: sow for seedlings from 12 April to 7 July; plant into a greenhouse from 10 May to 4 August; plant out into open ground from 31 May to 4 August. For plants and seeds, the places nearby include La Morera (garden centre, 1 km); addresses and opening hours are below.

Watermelon in Aranda de Duero: soil, season and weather

In Aranda de Duero the soil, not frost, sets the date: the last frost is over around 15 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 31 May, 46 days later.

Last spring frost	15 April
Top 7 cm of soil at 18 °C	31 May, 46 days after the last frost
Into an unheated greenhouse	10 May – 4 August; May outside: 8 °C at night, 21 °C by day; card 18–35 °C
First autumn frost	13 November, 166 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	29 July – 2 October
Days left for picking	107
Daylight	14:05 on 3 May, 14:58 on 31 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, July, has 2 rainy days

The same dates in Aranda de Duero hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Aranda de Duero: care after planting

Planted on 31 May: in the first weeks water every 5 days.

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

31 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 Aranda de Duero during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 30.9 °C. Months that stay below 18 °C even by day on average: November (12.6 °C). Nights average below 18 °C in every month of the season, from 3.6 °C to 15.8 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	21	8	45	9	14:31
June	26.4	12.8	37	8	15:11
July	30.8	15.5	7	2	14:55
August	30.9	15.8	8	2	13:53
September	25.1	11.5	24	4	12:31
October	20.2	8.2	54	8	11:09
November	12.6	3.6	63	11	9:52

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Aranda de Duero, Valladolid is 16 days earlier and Segovia 1 day later.

City	Distance	Date	Difference
Burgos	75 km	31 May – 8 August	same day
Palencia	78 km	25 May – 3 August	6 days earlier
Valladolid	86 km	15 May – 18 August	16 days earlier
Segovia	88 km	1 June – 30 July	1 day later
Soria	102 km	30 May – 31 July	1 day earlier
Guadalajara (Spain)	124 km	17 May – 15 August	14 days earlier

Where to buy watermelon plants and seeds near Aranda de Duero

Buy plants ready to set out from 31 May to 4 August (from 10 May to 4 August for an unheated greenhouse); seed for raising your own is sown from 12 April to 7 July. Within 15 km of Aranda de Duero OpenStreetMap lists 4 garden centres (collected 28 October 2026).

La Morera — garden centre
Carretera de La Aguilera, 09400 Aranda de Duero · 1 km
Cecoga — garden centre
3 km · cecoga.es
Castilla — garden centre
3 km
Plantas Nuñez — garden centre
5 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