When to plant tomatoes in Bayonne: 19 April – 27 August

In Bayonne, tomato: sow for seedlings from 5 February to 6 July; plant into a greenhouse from 29 March to 27 August; plant out into open ground from 19 April to 27 August. For plants and seeds, the places nearby include Pépizarra (garden centre, 2 km) and Comptoir Horticole Basco-Landais (garden centre, 4 km); addresses and opening hours are below.

Tomato 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 15 °C — the minimum on the tomato card — only around 19 April, 83 days later.

Last spring frost	26 January
Top 7 cm of soil at 15 °C	19 April, 83 days after the last frost
Into an unheated greenhouse	29 March – 27 August; March outside: 7.4 °C at night, 15.3 °C by day; card 16–27 °C
First autumn frost	17 December, 242 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	28 June – 5 November
Days left for picking	172
Daylight	11:02 on 26 February, 13:35 on 19 April
Watering outdoors when fruiting (card)	every 3 days; the driest month, July, has 10 rainy days

Tomato in Bayonne: care after planting

Planted on 19 April: in the first weeks water every 4 days.

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

19 April — feed: balanced (NPK)
17 May — feed: nitrogen

Pests and diseases of tomato 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 tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, August, averages 25.3 °C. Months that stay below 16 °C even by day on average: November (15.7 °C) and December (13.5 °C). Nights average below 16 °C in April–June and September–December (7–15.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
April	17.3	9.3	116	14	13:24
May	19.6	12.2	110	15	14:41
June	22.9	15.8	113	13	15:24
July	24.4	17.5	63	10	15:07
August	25.3	17.8	71	10	14:00
September	23.4	15.5	121	13	12:33
October	20.8	12.9	115	13	11:05
November	15.7	8.7	218	16	9:43
December	13.5	7	172	14	8:59

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

All the nearest cities on our list plant tomato later than Bayonne; the closest date is in San Sebastián, 12 days later.

City	Distance	Date	Difference
San Sebastián	45 km	1 May – 13 August	12 days later
Pamplona	77 km	14 May – 10 August	25 days later
Pau	92 km	4 May – 14 August	15 days later
Vitoria-Gasteiz	121 km	13 May – 4 August	24 days later
Bilbao	121 km	12 May – 5 September	23 days later
Jaca	129 km	1 June – 11 July	43 days later

Where to buy tomato plants and seeds near Bayonne

Buy plants ready to set out from 19 April to 27 August (from 29 March to 27 August for an unheated greenhouse); seed for raising your own is sown from 5 February to 6 July. Within 15 km of Bayonne OpenStreetMap lists 13 garden centres, 1 farm-supply shop, 20 markets and 34 farm shops (collected 27 October 2026).

Comptoir Horticole Basco-Landais — garden centre
Chemin de la Humère 19, 64100 Bayonne · Mon–Fri 08:00–12:00, 14:00–18:00 · 4 km · chbl.fr
Jardinerie Dicharry — garden centre
Chemin de Lavigne 298, 40220 Tarnos · Mon–Sat 09:15–12:00, 14:15–19:00; Sun 15:00–18:00 · 5 km · jardinerie-dicharry.fr
Jardiland — garden centre
Mon–Sat 09:30–19:00; Sun 10:00–12:30, 14:30–18:30 · 10 km · jardiland.com
Pépizarra — garden centre
Mon–Sat 10:30–18:30 · 2 km · pepizarra.com

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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