When to plant tomatoes in St. Gallen: 30 May – 29 July

In St. Gallen, tomato: sow for seedlings from 18 March to 7 June; plant into a greenhouse from 9 May to 29 July; plant out into open ground from 30 May to 29 July. For plants and seeds, the places nearby include Landi (garden centre, 10 km) and Gärtnerei & Blumen Urs Keller (garden centre, 14 km); addresses and opening hours are below.

Tomato in St. Gallen: soil, season and weather

In St. Gallen the soil, not frost, sets the date: the last frost is over around 14 April, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 30 May, 46 days later.

Last spring frost	14 April
Top 7 cm of soil at 15 °C	30 May, 46 days after the last frost
Into an unheated greenhouse	9 May – 29 July; May outside: 8.4 °C at night, 17.2 °C by day; card 16–27 °C
First autumn frost	18 November, 172 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	8 August – 7 October
Days left for picking	102
Daylight	13:12 on 8 April, 15:37 on 30 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, November, has 13 rainy days

Tomato in St. Gallen: care after planting

Planted on 30 May: in the first weeks water every 4 days.

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

30 May — feed: balanced (NPK)
27 June — 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 St. Gallen during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, July, averages 23.7 °C. Months that stay below 16 °C even by day on average: October (14.5 °C) and November (7.9 °C). Nights average below 16 °C in every month of the season, from 2 °C to 14.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	17.2	8.4	133	16	15:05
June	22.7	13.4	131	15	15:56
July	23.7	14.9	130	16	15:36
August	23.5	14.8	155	13	14:18
September	19.1	11.1	108	12	12:37
October	14.5	7.2	98	12	10:56
November	7.9	2	89	13	9:21

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

Around St. Gallen, Freiburg im Breisgau is 17 days earlier and Locarno 40 days later.

City	Distance	Date	Difference
Zurich	63 km	29 May – 27 July	1 day earlier
Lucerne	90 km	15 June – 30 June	16 days later
Freiburg im Breisgau	130 km	13 May – 27 July	17 days earlier
Basel	135 km	14 May – 31 July	16 days earlier
Bellinzona	139 km	28 May – 26 July	2 days earlier
Locarno	146 km	9 July – 14 July	40 days later

Where to buy tomato plants and seeds near St. Gallen

Buy plants ready to set out from 30 May to 29 July (from 9 May to 29 July for an unheated greenhouse); seed for raising your own is sown from 18 March to 7 June. Within 15 km of St. Gallen OpenStreetMap lists 7 garden centres, 3 farm-supply shops, 1 plant nursery, 3 markets and 24 farm shops (collected 27 October 2026).

Landi — garden centre
Bischofszellerstrasse 126, 9200 Gossau SG · Mon–Fri 08:00–18:30; Sat 08:00–16:00 · 10 km · landifuerstenland.ch
Gärtnerei & Blumen Urs Keller — garden centre
Kirchstrasse 10, 8588 Zihlschlacht · Mon 13:30–18:30; Tue–Fri 08:00–12:00, 13:30–18:30; Sat 08:00–12:00, 13:30–16:00; public holidays closed · 14 km · blumen-keller.ch
Gärtnerei Benz — garden centre
Brunnenackerstrasse 4, 9437 Marbach SG · Mon–Fri 08:00–12:00 · 15 km · benzgaertnerei.ch
Landi — garden centre
Hauptstrasse 10, 9105 Schönengrund · 15 km · landisaentis.ch

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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