When to plant watermelons in Timaru: 19 December – 23 February

In Timaru, watermelon: sow for seedlings from 31 October to 26 January; plant into a greenhouse from 28 November to 23 February; plant out into open ground from 19 December to 23 February.

Watermelon in Timaru: soil, season and weather

In Timaru the soil, not frost, sets the date: the last frost is over around 22 September, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 19 December, 88 days later.

Last spring frost	22 September
Top 7 cm of soil at 18 °C	19 December, 88 days after the last frost
Into an unheated greenhouse	28 November – 23 February; November outside: 9.6 °C at night, 18.7 °C by day; card 18–35 °C
First autumn frost	3 June, 167 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	16 February – 22 April
Days left for picking	108
Daylight	14:56 on 21 November, 15:32 on 19 December
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 9 rainy days

The same dates in Timaru hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Timaru: care after planting

Planted on 19 December: in the first weeks water every 5 days.

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

19 December — feed: balanced (NPK)

Pests and diseases of watermelon 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 Timaru during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, February, averages 21.4 °C. Months that stay below 18 °C even by day on average: April (17.2 °C), May (14.5 °C) and June (11.4 °C). Nights average below 18 °C in every month of the season, from 3.3 °C to 12.6 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
December	20.3	11.5	85	14	15:30
January	21.2	12.6	72	11	15:09
February	21.4	12.4	66	9	13:52
March	19.6	10.9	75	12	12:27
April	17.2	8	73	10	10:53
May	14.5	5.6	52	9	9:35
June	11.4	3.3	49	9	8:52

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Timaru, Christchurch is 18 days earlier and Nelson 1 day later.

City	Distance	Date	Difference
Christchurch	147 km	1 December – 24 February	18 days earlier
Dunedin	175 km	3 December – 10 February	16 days earlier
Queenstown	217 km	16 December – 8 February	3 days earlier
Invercargill	318 km	4 December – 27 February	15 days earlier
Nelson	384 km	20 December – 11 March	1 day later
Blenheim	389 km	11 December – 19 February	8 days earlier

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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