Runner bean · Brussels, Brussels Capital, Belgium
When to plant runner beans in Brussels
Main outdoor window
20 Apr - 4 May
The window this page is built around.
Timed from last spring frost
13 April
In Brussels, on your chosen risk.
Ready to pick
19 Jun - 9 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 Brussels
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
30 Mar - 13 Apr
Two weeks before your last frost, under cover or on a windowsill.
Sow direct
20 Apr - 4 May
One week after your last frost.
Plant out
20 Apr - 4 May
One week after your last frost.
Harvest
19 Jun - 9 Jul
Runner beans through the year
Against the frost risk in Brussels
Why these dates
Two weeks in pots gives a head start and protects seed from mice. Plant out once the supports are up and frost risk has passed.
Frost kills the vine, but runner beans tolerate cool cloudy weather that would stall a French bean. Flowers drop above 30C.
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. Runner beans are timed from 2 weeks before that frost for an indoor start, with planting out 1 weeks after it, and this page simply resolves those offsets against the frost date computed for Brussels.
The median frost-free season here is 216 days, against 60 to 80 days to maturity for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Brussels
Other vegetables to time
Growing runner beans in Brussels
When should I plant runner beans in Brussels?
Aim for 20 Apr - 4 May in an average year. If you would rather not gamble on the weather, wait until 30 Apr - 14 May - by then frost has finished in nine years out of ten.
When will runner beans be ready to harvest in Brussels?
Expect to start picking around 19 Jun - 9 Jul, based on 60 to 80 days to maturity from the planting date calculated for this location.
How much frost will runner beans tolerate?
Frost kills the vine, but runner beans tolerate cool cloudy weather that would stall a French bean. Flowers drop above 30C.