When to plant watermelons in Gwangju: 17 May – 14 August

In Gwangju, watermelon: sow for seedlings from 29 March to 17 July; plant into a greenhouse from 26 April to 14 August; plant out into open ground from 17 May to 14 August.

Watermelon in Gwangju: soil, season and weather

In Gwangju the soil, not frost, sets the date: the last frost is over around 1 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 17 May, 46 days later.

Last spring frost	1 April
Top 7 cm of soil at 18 °C	17 May, 46 days after the last frost
Into an unheated greenhouse	26 April – 14 August; April outside: 7.4 °C at night, 18.8 °C by day; card 18–35 °C
First autumn frost	23 November, 190 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	15 July – 12 October
Days left for picking	131
Daylight	13:12 on 19 April, 14:03 on 17 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 5 rainy days

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

Watermelon in Gwangju: care after planting

Planted on 17 May: in the first weeks water every 5 days.

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

17 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 Gwangju during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 30.4 °C. Months that stay below 18 °C even by day on average: November (13.9 °C). Nights average below 18 °C in May, June and October, November (4.4–17.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	23.3	12.2	118	9	14:00
June	27.2	17.8	176	12	14:31
July	29.4	22.5	287	18	14:19
August	30.4	23	217	16	13:30
September	26.3	18.5	178	12	12:26
October	20.1	11.3	94	7	11:20
November	13.9	4.4	50	5	10:20

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Gwangju, Jeju City is 11 days earlier and Jeonju 2 days later.

City	Distance	Date	Difference
Jeonju	77 km	19 May – 8 August	2 days later
Daejeon	140 km	17 May – 3 August	same day
Daegu	176 km	16 May – 12 August	1 day earlier
Jeju City	187 km	6 May – 9 September	11 days earlier
Busan	202 km	15 May – 13 August	2 days earlier
Ulsan	228 km	18 May – 7 August	1 day later

Where to buy watermelon plants and seeds near Gwangju

Buy plants ready to set out from 17 May to 14 August (from 26 April to 14 August for an unheated greenhouse); seed for raising your own is sown from 29 March to 17 July. Within 15 km of Gwangju OpenStreetMap lists 1 garden centre, 14 markets and 1 farm shop (collected 28 October 2026).

상무화훼단지 — market
3 km
무등시장 — market
5 km
중흥시장 — market
6 km
말바우시장 — market
7 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