When to plant tomatoes in Dundalk: 14 June – 31 July

In Dundalk, tomato: sow for seedlings from 2 April to 9 June; plant into a greenhouse from 24 May to 31 July; plant out into open ground from 14 June to 31 July. For plants and seeds, the places nearby include Hardys (farm supply, 2 km); addresses and opening hours are below.

Tomato in Dundalk: soil, season and weather

In Dundalk the soil, not frost, sets the date: the last frost is over around 20 March, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 14 June, 86 days later.

Last spring frost	20 March
Top 7 cm of soil at 15 °C	14 June, 86 days after the last frost
Into an unheated greenhouse	24 May – 31 July; May outside: 7.9 °C at night, 15.3 °C by day; card 16–27 °C
First autumn frost	20 November, 159 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	23 August – 9 October
Days left for picking	89
Daylight	14:34 on 23 April, 17:06 on 14 June
Watering outdoors when fruiting (card)	every 3 days; the driest month, June, has 15 rainy days

Tomato in Dundalk: care after planting

Planted on 14 June: in the first weeks water every 4 days.

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

14 June — feed: balanced (NPK)
12 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 Dundalk during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, July, averages 19 °C. Months that stay below 16 °C even by day on average: October (13.5 °C) and November (10 °C). Nights average below 16 °C in every month of the season, from 5 °C to 12.1 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
June	17.6	10.6	86	15	17:07
July	19	12.1	88	15	16:39
August	18.7	12	98	15	14:55
September	16.5	10.1	103	15	12:46
October	13.5	8.2	98	15	10:38
November	10	5	91	14	8:35

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

Around Dundalk, Athlone is 12 days earlier and Belfast 1 day later.

City	Distance	Date	Difference
Dublin	73 km	12 June – 4 August	2 days earlier
Belfast	73 km	15 June – 30 July	1 day later
Athlone	120 km	2 June – 6 August	12 days earlier
Derry	126 km	7 June – 1 August	7 days earlier
Letterkenny	137 km	7 June – 8 August	7 days earlier
Sligo	138 km	6 June – 1 August	8 days earlier

Where to buy tomato plants and seeds near Dundalk

Buy plants ready to set out from 14 June to 31 July (from 24 May to 31 July for an unheated greenhouse); seed for raising your own is sown from 2 April to 9 June. Within 15 km of Dundalk OpenStreetMap lists 2 garden centres, 2 farm-supply shops and 2 farm shops (collected 28 October 2026).

Hardys — farm supply
Lisdoo, Newry Road, Dundalk · 2 km · joesphwallsonline.com
Dundalk Garden Centre — garden centre
2 km
Carrive Grove Garden Centre — garden centre
10 km
Corderry Fruit Farm — farm supply
9 km · corderry.ie

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