When to plant tomatoes in Namur: 16 May – 26 July

In Namur, tomato: sow for seedlings from 4 March to 4 June; plant into a greenhouse from 25 April to 26 July; plant out into open ground from 16 May to 26 July. For plants and seeds, the places nearby include Tournesols Cognelée (garden centre, 5 km) and 4 Saisons (garden centre, 8 km); addresses and opening hours are below.

Tomato in Namur: soil, season and weather

In Namur the soil, not frost, sets the date: the last frost is over around 11 April, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 16 May, 35 days later.

Last spring frost	11 April
Top 7 cm of soil at 15 °C	16 May, 35 days after the last frost
Into an unheated greenhouse	25 April – 26 July; April outside: 4.5 °C at night, 13.9 °C by day; card 16–27 °C
First autumn frost	15 November, 183 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	25 July – 4 October
Days left for picking	113
Daylight	12:27 on 25 March, 15:30 on 16 May
Watering outdoors when fruiting (card)	every 3 days; the driest month, August, has 12 rainy days

Tomato in Namur: care after planting

Planted on 16 May: in the first weeks water every 4 days.

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

16 May — feed: balanced (NPK)
13 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 Namur during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, August, averages 23.1 °C. Months that stay below 16 °C even by day on average: October (15.2 °C) and November (9.6 °C). Nights average below 16 °C in every month of the season, from 4.3 °C to 13.9 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	18	8.2	68	11	15:27
June	21.8	12.5	76	11	16:25
July	22.8	13.5	70	12	16:02
August	23.1	13.9	62	12	14:34
September	19.8	11.4	65	11	12:41
October	15.2	8.8	75	13	10:48
November	9.6	4.3	67	13	9:01

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

4 of the nearest cities share Namur's date.

City	Distance	Date	Difference
Charleroi	31 km	16 May – 26 July	same day
Leuven	47 km	10 May – 2 August	6 days earlier
Liège	53 km	16 May – 30 July	same day
Brussels	56 km	16 May – 2 August	same day
Hasselt	61 km	10 May – 29 July	6 days earlier
Mons	65 km	16 May – 30 July	same day

Where to buy tomato plants and seeds near Namur

Buy plants ready to set out from 16 May to 26 July (from 25 April to 26 July for an unheated greenhouse); seed for raising your own is sown from 4 March to 4 June. Within 15 km of Namur OpenStreetMap lists 14 garden centres, 2 plant nurseries, 3 markets and 11 farm shops (collected 27 October 2026).

Tournesols Cognelée — garden centre
Chaussée de Louvain 929, 5022 Cognelée · Mon–Sat 09:00–19:00; Sun, public holidays 09:00–18:00 · 5 km · tournesols.com
4 Saisons — garden centre
Chaussée de Nivelles 298a, 5020 Temploux · Mon–Sat 09:00–18:00; Sun 09:30–16:00; Tue closed · 8 km
Aveve — garden centre
Rue des Six Bras 41, 5170 Bois-de-Villers · Mon–Sat 09:00–18:00 · 10 km
Jardin Loisirs — garden centre
Chaussée de Namur 141, 5030 Gembloux · Tue–Fri 09:00–18:30; Sat 09:00–18:00; Sun 09:15–12:15 · 15 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.

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