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When to plant watermelons in Bayonne: 28 May – 7 September

In Bayonne, watermelon: sow for seedlings from 9 April to 10 August; plant into a greenhouse from 7 May to 7 September; plant out into open ground from 28 May to 7 September. For plants and seeds, the places nearby include Gaec Laporte "Passion fruits rouges" (farm shop, 3 km) and Ferme Dache Dise (farm shop, 4 km); addresses and opening hours are below.

Watermelon in Bayonne: soil, season and weather

In Bayonne the soil, not frost, sets the date: the last frost is over around 26 January, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 28 May, 122 days later.

Last spring frost26 January
Top 7 cm of soil at 18 °C28 May, 122 days after the last frost
Into an unheated greenhouse7 May – 7 September; May outside: 12.2 °C at night, 19.6 °C by day; card 18–35 °C
First autumn frost17 December, 203 days after the start
Days in the bed to the first harvest (card)59
First harvest, if planted in this window26 July – 5 November
Days left for picking144
Daylight14:05 on 30 April, 15:05 on 28 May
Watering outdoors when fruiting (card)every 5 days; the driest month, July, has 10 rainy days

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

Watermelon in Bayonne: care after planting

Planted on 28 May: in the first weeks water every 5 days.

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

  • 28 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 Bayonne during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 25.3 °C. Months that stay below 18 °C even by day on average: November (15.7 °C) and December (13.5 °C). Nights average below 18 °C in every month of the season, from 7 °C to 17.8 °C.

MonthDay, °CNight, °CRain, mmRainy daysDaylight on the 15th
May19.612.21101514:41
June22.915.81131315:24
July24.417.5631015:07
August25.317.8711014:00
September23.415.51211312:33
October20.812.91151311:05
November15.78.7218169:43
December13.57172148:59

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

All the nearest cities on our list plant watermelon later than Bayonne; the closest date is in Pamplona, 4 days later.

CityDistanceDateDifference
San Sebastián45 km8 June – 24 August11 days later
Pamplona77 km1 June – 21 August4 days later
Pau92 km2 June – 25 August5 days later
Vitoria-Gasteiz121 km4 June – 15 August7 days later
Bilbao121 km2 June – 16 September5 days later
Jaca129 km19 June – 22 July22 days later

Where to buy watermelon plants and seeds near Bayonne

Buy plants ready to set out from 28 May to 7 September (from 7 May to 7 September for an unheated greenhouse); seed for raising your own is sown from 9 April to 10 August. Within 15 km of Bayonne OpenStreetMap lists 13 garden centres, 1 farm-supply shop, 20 markets and 34 farm shops (collected 27 October 2026).

Places: © OpenStreetMap contributors, ODbL.

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

When to plant watermelons in Bayonne?

In Bayonne, watermelon: sow for seedlings from 9 April to 10 August; plant into a greenhouse from 7 May to 7 September; plant out into open ground from 28 May to 7 September.

When to sow watermelons for seedlings in Bayonne?

Sow for seedlings from 9 April to 10 August.

When is the last spring frost in Bayonne?

Last spring frost around 26 January, first autumn frost around 17 December.

Other crops in Bayonne, with their dates