At a glance
- Brussels sprouts are the patience crop par excellence: they stand in the bed for almost half a year before the first sprouts are ripe.
- The most important trick for firm sprouts is a firm, well-settled soil. On loose, over-fertilised soil they stay loose and open.
- In autumn you top the growing tip. Then the plant puts its strength into the sprouts instead of into height, and they firm up more evenly.
- As with kale, cold makes it milder. Harvest from the bottom up all through winter.
Brussels sprouts demand of the gardener a virtue that has grown rare in the bed: patience. From planting in early summer to the first harvest in late autumn, a good four to five months pass in which seemingly little happens. But the wait pays off: hardly any vegetable supplies so long, so fresh and so winter-hardy.
The little sprouts are really side buds that sit close together along the stem. So they become firm and closed rather than loose and leafy, two things matter, which this article explains: the right soil and the right cut.
Half a year of patience
Brussels sprouts are sown from April and planted in May or June. Then they grow all summer into a tall stem, without much yet to see below. Only in autumn do the sprouts form in the leaf axils, from the bottom up.
Harvest starts in November and then runs all through winter, often into February. As with kale, the rule is: a few cold nights do the flavour good and take away the bitterness. Frost and snow do it no harm, you simply keep harvesting.
Firm soil and topping
The most common frustration with Brussels sprouts is loose, open sprouts instead of firm balls. Two causes are almost always behind it, and both can be avoided.
First the soil: Brussels sprouts want it firm. On freshly dug, loose or heavily nitrogen-fertilised soil they drive lots of leaf, but the sprouts stay loose. So set them into well-settled soil and fertilise in moderation. Second the topping: if you cut off the growing tip in October, height growth stops and the plant pushes its strength into the existing sprouts, which then firm up more evenly and faster.
The secrets of firm sprouts
- Firm soil
Brussels sprouts like it firm underfoot, not loose. On too soft soil the tall stems topple and the sprouts stay open. Do not deep-dig freshly before planting.
- Fertilise in moderation
Too much nitrogen gives lots of leaf mass and loose sprouts. A nutrient-rich but not over-fertilised soil brings the firm balls.
- Top the growing tip
In October cut off the topmost bud. That stops height growth and lets the sprouts firm up evenly. The cut tip is edible.
- Harvest from below
The lowest sprouts ripen first. Snap them off one by one and work your way up over the weeks, so you crop one plant all winter.
How you grow Brussels sprouts
Sow from April
Sow into a seedbed or pots. Brussels sprouts need an early start, because the crop is so long.
Plant in May or June
Set 50 to 60 centimetres apart into firm, not freshly dug soil. Firming down helps.
Top in October
Cut off the growing tip once the lower sprouts are pea-sized. That brings evenly firm sprouts.
Harvest from November, from below
Snap off the ripe lower sprouts one by one and keep harvesting up the stem through winter, often into February.
The cabbage white is the enemy here too
Like all cabbages, Brussels sprouts are popular with the cabbage white in summer, whose caterpillars riddle the leaves with holes. A fine protective net over the bed is the simplest protection. More on it in Protecting cabbages. A thought-through crop rotation also keeps cabbage diseases out of the soil.
Firm soil, fertilise in moderation, top in October. Then the patience crop rewards you with firm sprouts all winter.
The core rule for Brussels sprouts
Frequently asked questions
Why do my Brussels sprouts turn loose and open?
Almost always it is down to soil that is too loose or too much nitrogen. Brussels sprouts want it firm underfoot and fertilised in moderation. Do not set them into freshly deep-dug soil, firm them down and top the growing tip in October, then the sprouts firm up.
When do you plant and when harvest Brussels sprouts?
They are sown from April, planted in May or June. They are harvested from November all through winter, often into February. Brussels sprouts are a long patience crop that stands in the bed for almost half a year.
Do I have to cut off the growing tip of Brussels sprouts?
It pays off. If you cut off the topmost bud in October, height growth stops and the plant puts its strength into the sprouts. They firm up more evenly and faster as a result. The cut tip is edible like a small cabbage.
Do Brussels sprouts tolerate frost?
Yes, Brussels sprouts are very winter-hardy and survive frost and snow easily. As with kale, a few cold nights even make them milder and sweeter. You can harvest them fresh from the bed all through winter.
How do you harvest Brussels sprouts correctly?
From the bottom up. The lowest sprouts ripen first, snap them off one by one with a twist. In the weeks after you work your way up the stem. That way you crop a single plant over many weeks.
Sources
- Julius Kühn Institute: Brussels sprouts in the home and allotment garden
- Bavarian State Institute for Viticulture and Horticulture (LWG): Brussels sprouts, growing and harvest
- Related in the magazine: Kale and The garden in May
Spotted a mistake?
