When to plant watermelons in Devonport: 12 December – 16 March

In Devonport, watermelon: sow for seedlings from 24 October to 17 February; plant into a greenhouse from 21 November to 16 March; plant out into open ground from 12 December to 16 March. For plants and seeds, the places nearby include Plants Plus Nursery Devonport (plant nursery, 0 km) and Big Pot Nursery (garden centre, 11 km); addresses and opening hours are below.

Watermelon in Devonport: soil, season and weather

In Devonport the soil, not frost, sets the date: the last frost is over around 23 August, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 12 December, 111 days later.

Last spring frost	23 August
Top 7 cm of soil at 18 °C	12 December, 111 days after the last frost
Into an unheated greenhouse	21 November – 16 March; November outside: 9.7 °C at night, 18.8 °C by day; card 18–35 °C
First autumn frost	25 June, 196 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	9 February – 14 May
Days left for picking	137
Daylight	14:23 on 14 November, 15:05 on 12 December
Watering outdoors when fruiting (card)	every 5 days; the driest month, February, has 7 rainy days

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

Watermelon in Devonport: care after planting

Planted on 12 December: in the first weeks water every 5 days.

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

12 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 Devonport during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 23.4 °C. Months that stay below 18 °C even by day on average: April (17.7 °C), May (14.8 °C) and June (12.7 °C). Nights average below 18 °C in every month of the season, from 5.8 °C to 13.3 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
December	21	11.1	63	10	15:07
January	23.4	13.3	73	10	14:49
February	22.2	12.7	52	7	13:41
March	20.9	11.8	67	9	12:25
April	17.7	9.4	73	9	11:01
May	14.8	7.4	84	11	9:51
June	12.7	5.8	107	11	9:13

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Devonport, Albury is 33 days earlier and Ballarat 6 days later.

City	Distance	Date	Difference
Launceston	71 km	13 December – 27 February	1 day later
Geelong	378 km	from 23 November	19 days earlier
Melbourne	393 km	12 November – 15 March	30 days earlier
Ballarat	455 km	18 December – 9 March	6 days later
Bendigo	523 km	16 November – 9 March	26 days earlier
Albury	570 km	9 November – 10 March	33 days earlier

Where to buy watermelon plants and seeds near Devonport

Buy plants ready to set out from 12 December to 16 March (from 21 November to 16 March for an unheated greenhouse); seed for raising your own is sown from 24 October to 17 February. Within 15 km of Devonport OpenStreetMap lists 1 garden centre and 1 plant nursery (collected 28 October 2026).

Big Pot Nursery — garden centre
Melrose Road 1032, 7310 · 11 km
Plants Plus Nursery Devonport — plant nursery
Steele Street 147-149, 7310 · 0 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