When to plant tomatoes in Blenheim: 30 October – 8 February

In Blenheim, tomato: sow for seedlings from 18 August to 18 December; plant into a greenhouse from 9 October to 8 February; plant out into open ground from 30 October to 8 February. For plants and seeds, the places nearby include Golden Mile Produce (farm shop, 6 km); addresses and opening hours are below.

Tomato in Blenheim: soil, season and weather

In Blenheim the soil, not frost, sets the date: the last frost is over around 10 August, but the top 7 cm of soil reaches 15 °C — the minimum on the tomato card — only around 30 October, 81 days later.

Last spring frost	10 August
Top 7 cm of soil at 15 °C	30 October, 81 days after the last frost
Into an unheated greenhouse	9 October – 8 February; October outside: 8.8 °C at night, 17.8 °C by day; card 16–27 °C
First autumn frost	30 May, 213 days after the start
Days in the bed to the first harvest (card)	70
First harvest, if planted in this window	8 January – 18 April
Days left for picking	143
Daylight	11:28 on 8 September, 13:49 on 30 October
Watering outdoors when fruiting (card)	every 3 days; the driest month, January, has 7 rainy days

Tomato in Blenheim: care after planting

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

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

30 October — feed: balanced (NPK)
27 November — 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 Blenheim during the tomato season

No month of the season averages above the tomato card's 16–27 °C by day; the warmest, January, averages 23.3 °C. Months that stay below 16 °C even by day on average: May (15.7 °C). Nights average below 16 °C in every month of the season, from 8.2 °C to 14 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
October	17.8	8.8	71	11	13:09
November	19.9	11	69	11	14:27
December	21.8	12.9	78	10	15:09
January	23.3	14	50	7	14:51
February	23	13.8	65	6	13:42
March	21.1	12.3	61	8	12:25
April	18.3	10.2	75	7	11:00
May	15.7	8.2	72	9	9:50

ERA5 2016–2025, Open-Meteo

Tomato in nearby cities

Around Blenheim, Napier is 19 days earlier and Wellington 23 days later.

City	Distance	Date	Difference
Nelson	63 km	11 November – 29 February	12 days later
Wellington	73 km	from 22 November	23 days later
Palmerston North	189 km	29 October – 29 February	1 day earlier
Christchurch	249 km	30 October – 13 February	same day
Napier	336 km	from 11 October	19 days earlier
Timaru	389 km	4 November – 12 February	5 days later

Where to buy tomato plants and seeds near Blenheim

Buy plants ready to set out from 30 October to 8 February (from 9 October to 8 February for an unheated greenhouse); seed for raising your own is sown from 18 August to 18 December. Within 15 km of Blenheim OpenStreetMap lists 1 market and 1 farm shop (collected 28 October 2026).

Marlborough Farmers' Market — market
Maxwell Road · Sun 09:00–12:00 · 2 km
Golden Mile Produce — farm shop
Sat 14:00–18:00 · 6 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