Greenly Garden

When to plant pumpkins in Jeju City: 6 May – 24 August

In Jeju City, pumpkin: sow for seedlings from 4 March to 13 July; plant into a greenhouse from 15 April to 24 August; plant out into open ground from 6 May to 24 August.

Pumpkin in Jeju City: soil, season and weather

In Jeju City the soil, not frost, sets the date: the last frost is over around 18 February, but the top 7 cm of soil reaches 18 °C — the minimum on the pumpkin card — only around 6 May, 77 days later.

Last spring frost18 February
Top 7 cm of soil at 18 °C6 May, 77 days after the last frost
First autumn frost19 December, 227 days after the start
Days in the bed to the first harvest (card)75
First harvest, if planted in this window20 July – 7 November
Days left for picking152
Daylight12:17 on 25 March, 13:39 on 6 May
Watering outdoors when fruiting (card)every 5 days; the driest month, December, has 14 rainy days

The same dates in Jeju City hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Watermelon.

Pumpkin in Jeju City: care after planting

Planted on 6 May: in the first weeks water every 4 days.

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

  • 27 May — feed: nitrogen

Pests and diseases of pumpkin 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 Jeju City during the pumpkin season

About 1558 mm of rain falls in the season; December is the driest month (85 mm) and September the wettest (354 mm).

MonthDay, °CNight, °CRain, mmRainy daysDaylight on the 15th
May21.815.71481113:53
June2519.92081414:22
July2924.62331814:10
August29.925.42401913:25
September26.1223541912:25
October20.816.41821311:23
November15.710.41081110:27
December9.95.285149:57

ERA5 2016–2025, Open-Meteo

Pumpkin in nearby cities

All the nearest cities on our list plant pumpkin later than Jeju City; the closest date is in Busan, 9 days later.

CityDistanceDateDifference
Gwangju187 km17 May – 29 July11 days later
Jeonju263 km19 May – 23 July13 days later
Busan299 km15 May – 28 July9 days later
Daegu324 km16 May – 27 July10 days later
Daejeon326 km17 May – 18 July11 days later
Ulsan342 km18 May – 22 July12 days later

Where to buy pumpkin plants and seeds near Jeju City

Buy plants ready to set out from 6 May to 24 August (from 15 April to 24 August for an unheated greenhouse); seed for raising your own is sown from 4 March to 13 July. Within 15 km of Jeju City OpenStreetMap lists 1 garden centre, 7 markets and 1 farm shop (collected 28 October 2026).

Places: © OpenStreetMap contributors, ODbL.

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

When to plant pumpkins in Jeju City?

In Jeju City, pumpkin: sow for seedlings from 4 March to 13 July; plant into a greenhouse from 15 April to 24 August; plant out into open ground from 6 May to 24 August.

When to sow pumpkins for seedlings in Jeju City?

Sow for seedlings from 4 March to 13 July.

When is the last spring frost in Jeju City?

Last spring frost around 18 February, first autumn frost around 19 December.

Other crops in Jeju City, with their dates