Safe to Plant

Sweetcorn · Daejeon, Daejeon, South Korea

When to plant sweetcorn in Daejeon

Main outdoor window

15-29 Apr

The window this page is built around.

Timed from last spring frost

8 April

In Daejeon, on your chosen risk.

Ready to pick

14 Jun - 24 Jul

If you plant at the start of the window.

The average last frost. Half of all years are later than this.

Step by step in Daejeon

Each window is a range, not a single day. Earlier in the range buys you a longer season; later in it buys you a safer one.

Sow direct

15-29 Apr

One week after your last frost.

Harvest

14 Jun - 24 Jul

Sow in succession. A single sowing gives you a single glut. Sow a short row every 14 days through the window above and you get a steady supply instead.
Frost tolerance
Tender
Damaged below
0°C (32°F)
Days to maturity
60–100
Min soil temp
15°C (59°F)
Spacing
30 cm
Sowing depth
30 mm (1.2 in)
Sun
Full

Sweetcorn through the year

Against the frost risk in Daejeon

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Frost risk Sow direct Harvest Today

Why these dates

Seed rots in cold wet soil. Sowing a week after last frost into 15C soil beats sowing on the frost date into 10C soil almost every time.

Seedlings survive a very light frost if the growing point is still below soil level, but growth stalls. Mature plants are killed outright.

Seed packets and extension guides express timing as weeks either side of the last spring frost, because that is the only reference point that travels. Sweetcorn are timed for direct sowing 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Daejeon.

The median frost-free season here is 208 days, against 60 to 100 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.

See every crop timed for Daejeon →

Growing sweetcorn in Daejeon

When should I plant sweetcorn in Daejeon?

Aim for 15-29 Apr in an average year. If you would rather not gamble on the weather, wait until 24 Apr - 8 May - by then frost has finished in nine years out of ten.

When will sweetcorn be ready to harvest in Daejeon?

Expect to start picking around 14 Jun - 24 Jul, based on 60 to 100 days to maturity from the planting date calculated for this location.

How much frost will sweetcorn tolerate?

Seedlings survive a very light frost if the growing point is still below soil level, but growth stalls. Mature plants are killed outright.