When to plant tomatoes in Leuven: 10 May – 2 August

In Leuven, tomato: sow for seedlings from 26 February to 11 June; plant into a greenhouse from 19 April to 2 August; plant out into open ground from 10 May to 2 August. For plants and seeds, the places nearby include Aveve (garden centre, 2 km) and Van Goidsenhoven (garden centre, 7 km); addresses and opening hours are below.

Tomato in Leuven: soil, season and weather

In Leuven the soil, not frost, sets the date: the last frost is over around 19 April, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 10 May, 21 days later.

Last spring frost	19 April
Top 7 cm of soil at 15 °C	10 May, 21 days after the last frost
Into an unheated greenhouse	19 April – 2 August; April outside: 5 °C at night, 14.8 °C by day; card 16–27 °C
First autumn frost	22 November, 196 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	19 July – 11 October
Days left for picking	126
Daylight	12:04 on 19 March, 15:15 on 10 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, September, has 11 rainy days

Tomato in Leuven: care after planting

Planted on 10 May: in the first weeks water every 4 days.

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

10 May — feed: balanced (NPK)
7 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 Leuven during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, August, averages 23.7 °C. Months that stay below 16 °C even by day on average: October (15.9 °C) and November (10.2 °C). Nights average below 16 °C in every month of the season, from 4.7 °C to 14.3 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	19.1	8.8	69	11	15:30
June	22.7	13.1	81	12	16:30
July	23.5	14	79	12	16:06
August	23.7	14.3	69	13	14:36
September	20.6	11.8	62	11	12:42
October	15.9	9.3	81	13	10:47
November	10.2	4.7	70	14	8:59

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

2 of the nearest cities share Leuven's date.

City	Distance	Date	Difference
Brussels	25 km	16 May – 2 August	6 days later
Antwerp	43 km	10 May – 2 August	same day
Hasselt	45 km	10 May – 29 July	same day
Namur	47 km	16 May – 26 July	6 days later
Charleroi	55 km	16 May – 26 July	6 days later
Liège	67 km	16 May – 30 July	6 days later

Where to buy tomato plants and seeds near Leuven

Buy plants ready to set out from 10 May to 2 August (from 19 April to 2 August for an unheated greenhouse); seed for raising your own is sown from 26 February to 11 June. Within 15 km of Leuven OpenStreetMap lists 31 garden centres, 1 plant nursery, 7 markets and 21 farm shops (collected 27 October 2026).

Aveve — garden centre
Aarschotsesteenweg 94;88, 3012 Leuven · Mon–Fri 09:00–18:30; Sat 09:00–18:00 · 2 km · aveve.be
Van Goidsenhoven — garden centre
Kortrijksebaan 54, 3220 Holsbeek · Mon–Fri 10:00–18:00; Sat 09:00–18:00; public holidays closed · 7 km · vangoidsenhoven.be
Winnepenninckx — garden centre
Kelfsstraat 9 · Tue–Fri 08:00–12:00, 13:00–18:00; Sat 08:00–17:00 · 9 km · winnepenninckx.be
Robeet boomkwekerijen — garden centre
Donkerstraat 8, 3080 Tervuren · Mon–Sat 08:00–12:00, 13:00–17:00; Thu, Sun, public holidays closed · 11 km · robeetboomkwekerijen.be

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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