When to plant tomatoes in Grenoble: 20 June – 5 July

In Grenoble, tomato: sow for seedlings from 8 April to 14 May; plant into a greenhouse from 30 May to 5 July; plant out into open ground from 20 June to 5 July. For plants and seeds, the places nearby include Paquet Jardin (garden centre, 4 km) and Villaverde (garden centre, 5 km); addresses and opening hours are below.

Tomato in Grenoble: soil, season and weather

In Grenoble the soil, not frost, sets the date: the last frost is over around 5 May, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 20 June, 46 days later. 127 days separate planting out (20 June) from the first autumn frost (25 October); the card's 70 days to the first harvest leave 57 for picking, so a start 8 weeks late would still fit.

Last spring frost	5 May
Top 7 cm of soil at 15 °C	20 June, 46 days after the last frost
Into an unheated greenhouse	30 May – 5 July; May outside: 5 °C at night, 15.3 °C by day; card 16–27 °C
First autumn frost	25 October, 127 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	29 August – 13 September
Days left for picking	57
Daylight	14:10 on 29 April, 15:39 on 20 June
Watering outdoors when fruiting (card)	every 3 days; the driest month, July, has 9 rainy days

Tomato in Grenoble: care after planting

Planted on 20 June: in the first weeks water every 4 days.

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

20 June — feed: balanced (NPK)
18 July — 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 Grenoble during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, August, averages 22.8 °C. Months that stay below 16 °C even by day on average: October (14.1 °C). Nights average below 16 °C in every month of the season, from 4.3 °C to 11.7 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	20.6	10.1	130	13	15:37
July	22.7	11.7	83	9	15:19
August	22.8	11.7	87	8	14:08
September	18	7.7	101	11	12:35
October	14.1	4.3	128	11	11:01

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

All the nearest cities on our list plant tomato earlier than Grenoble; the closest date is in Annecy, 18 days earlier.

City	Distance	Date	Difference
Chambéry	45 km	13 May – 31 July	38 days earlier
Valence	70 km	1 May – 1 August	50 days earlier
Annecy	86 km	2 June – 25 July	18 days earlier
Lyon	93 km	2 May – 5 August	49 days earlier
Saint-Étienne	108 km	30 May – 28 July	21 days earlier
Geneva	117 km	28 May – 28 July	23 days earlier

Where to buy tomato plants and seeds near Grenoble

Buy plants ready to set out from 20 June to 5 July (from 30 May to 5 July for an unheated greenhouse); seed for raising your own is sown from 8 April to 14 May. Within 15 km of Grenoble OpenStreetMap lists 17 garden centres, 4 plant nurseries, 55 markets and 19 farm shops (collected 20 October 2026).

Paquet Jardin — garden centre
Chemin de la Revirée 46, 38240 Meylan · Mon–Sat 09:30–12:30, 14:00–19:00; Sun 09:30–12:30, 14:00–18:00; Jan Sun closed; Jul Sun closed; Aug Sun closed · 4 km · paquetjardin.com
Villaverde — garden centre
Rue des Montagnes de Lans 10, 38130 · Mon–Sat 09:30–12:00, 14:00–19:00 · 5 km · villaverde.fr
Botanic — garden centre
Route de la Doux 1063, 38330 Montbonnot-Saint-Martin · Mon–Sat 09:30–19:00; Sun 09:30–12:30, 14:00–18:00 · 9 km · botanic.com
Le jardin des connivences — garden centre
Chemin de l'Église 8, 38800 · Tue 16:00–19:00; Fri 09:30–12:30, 16:00–19:00; Sat 09:30–12:30 · 9 km · commande.kuupanda.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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