Persian buttercup · Brussels, Brussels Capital, Belgium
When to sow persian buttercups in Brussels
Main outdoor window
4-18 Oct
The window this page is built around.
Timed from last spring frost
13 April
In Brussels, on your chosen risk.
Ready to pick
1 Apr - 30 Jun
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.
Plant the corms
4-18 Oct
Four to six weeks before your first frost, so roots form before the ground cools.
In flower
1 Apr - 30 Jun
Persian buttercups through the year
Against the frost risk in Brussels
Why these dates
Where winters stay above about -7C, plant in autumn for spring flowers - this gives much the better crop. In colder gardens, start the corms indoors in late winter and plant out around the last frost, or grow them in a cold frame. Soak the claws for three or four hours before planting, points downward, 5cm deep.
Hardy only to about -7C, so autumn planting is limited to zone 8 and warmer. The foliage takes a light frost; a hard one kills the plant. It also stops flowering in real heat, so a hot spring simply ends the season early.
Persian buttercups are anchored to the first autumn frost rather than the last spring one, so the planting window on this page counts backwards from the end of the season in Brussels instead of forwards from its start.
Hardiness is not the obstacle here. Brussels is zone 8b, comfortably inside the range this crop is rated for, so an established plant should come through an average winter without protection.
The median frost-free season here is 216 days, against 90 to 120 days to first flower for this crop counted from sowing. That margin is what decides whether a late sowing is worth attempting.
Also in Brussels
Other flowers to time
Growing persian buttercups in Brussels
When should I plant persian buttercups in Brussels?
Aim for 4-18 Oct in an average year. If you would rather not gamble on the weather, wait until 9-23 Sep - by then frost has finished in nine years out of ten.
When will persian buttercups be ready to harvest in Brussels?
Expect to start picking around 1 Apr - 30 Jun, based on 90 to 120 days to maturity from the planting date calculated for this location.
How much frost will persian buttercups tolerate?
Hardy only to about -7C, so autumn planting is limited to zone 8 and warmer. The foliage takes a light frost; a hard one kills the plant. It also stops flowering in real heat, so a hot spring simply ends the season early.