When to plant cucumbers in Mannheim: 1 June – 5 September

In Mannheim, cucumber: sow for seedlings from 13 April to 8 August; plant into a greenhouse from 11 May to 5 September; plant out into open ground from 1 June to 5 September. For plants and seeds, the places nearby include Dehner (garden centre, 5 km) and Dehner (garden centre, 8 km); addresses and opening hours are below.

Cucumber in Mannheim: soil, season and weather

In Mannheim the soil, not frost, sets the date: the last frost is over around 14 April, but the top 7 cm of soil reaches 18 °C — the minimum on the cucumber card — only around 1 June, 48 days later.

Last spring frost	14 April
Top 7 cm of soil at 18 °C	1 June, 48 days after the last frost
Into an unheated greenhouse	11 May – 5 September; May outside: 9.7 °C at night, 19.9 °C by day; card 18–25 °C
First autumn frost	20 November, 172 days after the start
Days in the bed to the first harvest (card)	34
First harvest, if planted in this window	5 July – 9 October
Days left for picking	138
Daylight	14:47 on 4 May, 15:59 on 1 June
Watering outdoors when fruiting (card)	every 2 days; the driest month, August, has 11 rainy days

The same dates in Mannheim hold for Bell Pepper, Eggplant, Zucchini, Pumpkin and Watermelon.

Cucumber in Mannheim: care after planting

Planted on 1 June: in the first weeks water every 4 days.

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

8 June — feed: nitrogen

Pests and diseases of cucumber 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 Mannheim during the cucumber season

No month of the season averages above the cucumber card's 18–35 °C by day; the warmest, July, averages 26.2 °C. Months that stay below 18 °C even by day on average: October (16.1 °C) and November (9.3 °C). Nights average below 18 °C in every month of the season, from 3.6 °C to 16 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	25.3	14.7	69	11	16:15
July	26.2	15.8	67	10	15:53
August	26.2	16	63	11	14:28
September	21.8	12.2	69	10	12:40
October	16.1	8.4	84	13	10:51
November	9.3	3.6	73	14	9:08

ERA5 2016–2025, Open-Meteo

Cucumber in nearby cities

Around Mannheim, Karlsruhe is 2 days earlier and Stuttgart 4 days later.

City	Distance	Date	Difference
Karlsruhe	54 km	30 May – 4 September	2 days earlier
Wiesbaden	68 km	30 May – 8 September	2 days earlier
Frankfurt	71 km	4 June – 2 September	3 days later
Stuttgart	94 km	5 June – 24 August	4 days later
Saarbrücken	111 km	3 June – 3 September	2 days later
Strasbourg	115 km	1 June – 5 September	same day

Where to buy cucumber plants and seeds near Mannheim

Buy plants ready to set out from 1 June to 5 September (from 11 May to 5 September for an unheated greenhouse); seed for raising your own is sown from 13 April to 8 August. Within 15 km of Mannheim OpenStreetMap lists 30 garden centres, 3 farm-supply shops, 17 plant nurseries, 24 markets and 50 farm shops (collected 28 October 2026).

Pflanzenparadies — garden centre
Freiburger Straße 19, 69469 Weinheim · Mon–Fri 09:00–18:00; Sat 09:00–16:00 · 13 km · pflanzenparadies-weinheim.de
Pfisterer — garden centre
Hebelstraße 11, 69214 Eppelheim · Mon–Fri 09:00–12:00, 14:30–18:00; Sat 08:30–13:00 · 15 km · gaertnerei-pfisterer.de
Dehner — garden centre
Seckenheimer Landstraße 270, 68163 Mannheim · Mon–Sat 09:00–19:00 · 5 km
Dehner — garden centre
Oderstraße 5, 67071 Ludwigshafen am Rhein · Mon–Fri 09:00–19:00; Sat 09:00–18:00 · 8 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