When to plant watermelons in Busan: 15 May – 13 August

In Busan, watermelon: sow for seedlings from 27 March to 16 July; plant into a greenhouse from 24 April to 13 August; plant out into open ground from 15 May to 13 August.

Watermelon in Busan: soil, season and weather

In Busan the soil, not frost, sets the date: the last frost is over around 19 March, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 15 May, 57 days later.

Last spring frost	19 March
Top 7 cm of soil at 18 °C	15 May, 57 days after the last frost
Into an unheated greenhouse	24 April – 13 August; April outside: 8.7 °C at night, 19 °C by day; card 18–35 °C
First autumn frost	22 November, 191 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	13 July – 11 October
Days left for picking	132
Daylight	13:08 on 17 April, 14:00 on 15 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 4 rainy days

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

Watermelon in Busan: care after planting

Planted on 15 May: in the first weeks water every 5 days.

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

15 May — 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 Busan during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 30.6 °C. Months that stay below 18 °C even by day on average: November (15.4 °C). Nights average below 18 °C in May (13.4 °C), October (12.3 °C) and November (5.1 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23.4	13.4	127	9	14:00
June	26.8	18.3	197	11	14:31
July	29.6	23	272	17	14:19
August	30.6	23.7	226	17	13:30
September	26.3	19.4	257	14	12:26
October	21.3	12.3	99	8	11:20
November	15.4	5.1	42	4	10:20

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Busan, Fukuoka is 10 days earlier and Jeonju 4 days later.

City	Distance	Date	Difference
Ulsan	47 km	18 May – 7 August	3 days later
Daegu	88 km	16 May – 12 August	1 day later
Jeonju	188 km	19 May – 8 August	4 days later
Daejeon	200 km	17 May – 3 August	2 days later
Gwangju	202 km	17 May – 14 August	2 days later
Fukuoka	215 km	5 May – 11 September	10 days earlier

Where to buy watermelon plants and seeds near Busan

Buy plants ready to set out from 15 May to 13 August (from 24 April to 13 August for an unheated greenhouse); seed for raising your own is sown from 27 March to 16 July. Within 15 km of Busan OpenStreetMap lists 27 markets (collected 28 October 2026).

Gijang Market — market
15 km
거제시장 — market
0 km
Suyeoung Paldo Traditional Market — market
4 km
Millak Golmok Market — market
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