Soybean · Bonn, North Rhine-Westphalia, Germany
When to plant soybeans in Bonn
Main outdoor window
5-26 May
The window this page is built around.
Timed from last spring frost
21 April
In Bonn, on your chosen risk.
Ready to pick
29 Jul - 2 Sep
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 Bonn
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
5-26 May
Two weeks after your last frost.
Harvest
29 Jul - 2 Sep
Soybeans through the year
Against the frost risk in Bonn
Why these dates
Sow two weeks after the last frost into warm soil. Varieties are grouped by maturity for a given latitude, and a variety from the wrong group will either flower far too early or fail to finish at all - this matters more with soybeans than with almost any other crop.
No frost tolerance. Killed at 0C at both ends of the season.
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. Soybeans are timed for direct sowing 2 weeks after it, and this page simply resolves those offsets against the frost date computed for Bonn.
The median frost-free season here is 199 days, against 85 to 120 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Bonn
Other grains to time
Growing soybeans in Bonn
When should I plant soybeans in Bonn?
Aim for 5-26 May in an average year. If you would rather not gamble on the weather, wait until 19 May - 9 Jun - by then frost has finished in nine years out of ten.
When will soybeans be ready to harvest in Bonn?
Expect to start picking around 29 Jul - 2 Sep, based on 85 to 120 days to maturity from the planting date calculated for this location.
How much frost will soybeans tolerate?
No frost tolerance. Killed at 0C at both ends of the season.