Amaranth · Gwangmyeong, Gyeonggi-do, South Korea
When to plant amaranth in Gwangmyeong
Main outdoor window
10 Apr - 1 May
The window this page is built around.
Timed from last spring frost
3 April
In Gwangmyeong, on your chosen risk.
Ready to pick
19 Jul - 18 Aug
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 Gwangmyeong
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.
Start indoors
6-27 Mar
Four weeks before your last frost, under cover or on a windowsill.
Sow direct
10 Apr - 1 May
One week after your last frost.
Plant out
17 Apr - 8 May
Two weeks after your last frost.
Harvest
19 Jul - 18 Aug
Amaranth through the year
Against the frost risk in Gwangmyeong
Why these dates
Sow after the last frost into warm soil. The seed is very fine and should barely be covered.
Killed by the first frost at either end of the season - it has no cold tolerance at all.
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. Amaranth are timed from 4 weeks before that frost for an indoor start, with planting out 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Gwangmyeong.
The median frost-free season here is 223 days, against 100 to 130 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Gwangmyeong
Other grains to time
Growing amaranth in Gwangmyeong
When should I plant amaranth in Gwangmyeong?
Aim for 10 Apr - 1 May in an average year. If you would rather not gamble on the weather, wait until 19 Apr - 10 May - by then frost has finished in nine years out of ten.
When will amaranth be ready to harvest in Gwangmyeong?
Expect to start picking around 19 Jul - 18 Aug, based on 100 to 130 days to maturity from the planting date calculated for this location.
How much frost will amaranth tolerate?
Killed by the first frost at either end of the season - it has no cold tolerance at all.