Brussels sprouts are the slowest crop on the plot and the most rewarding to get right at the end. After months of growth, the difference between a sweet, tight sprout and a loose, bitter one is mostly down to when and how you pick. The good news: sprouts are patient. A well-grown plant stands in the ground for weeks, so you can harvest a few at a time from autumn deep into winter.
This guide covers how to tell sprouts are ready, why frost improves them, how to pick so the plant keeps producing, and how to time a harvest for Christmas. For sowing and growing, start with our Brussels sprouts growing guide.
- Ready buttons firm and tight, 2.5–4 cm across
- Season early varieties from September; late ones until March
- Pick from the bottom of the stem upwards, a few at a time
- Flavour best after the first frosts, which sweeten the sprouts
How to tell Brussels sprouts are ready
Sprouts form from the bottom of the stem up, so the lowest ones are always ready first. A sprout is ready when it is firm and tightly closed, roughly the size of a large marble to a walnut: 2.5–4 cm across. Squeeze one gently: it should feel solid, not spongy. Leave them much longer and they open up into loose rosettes, known as "blown" sprouts, which are tougher and more bitter.
When the harvest starts depends on the variety and sowing date. Early types sown in March can be ready from September, mid-season types from November, and late varieties carry on through January to March. Growing two or three types gives you sprouts for most of the winter.
Why frost makes sprouts sweeter
Brussels sprouts are hardy, and cold works in your favour. When temperatures drop to freezing, the plant converts some of its stored starch into sugars, which act as a natural antifreeze in the cells. The result is a noticeably sweeter, milder sprout. That is why many gardeners wait for the first one or two frosts before starting the main harvest.
You do not need to pick frozen sprouts, though. If they are frozen solid on the plant, wait until they have thawed naturally in the day before picking; handling frozen sprouts bruises them.
How to pick Brussels sprouts
- Start at the bottom Take the lowest, largest sprouts first. The ones above keep growing and will be ready a week or two later.
- Snap them downwards Push each sprout down firmly and it breaks away cleanly. A small knife works for stubborn ones; cut close to the stem.
- Remove yellow leaves as you go Pull off yellowing lower leaves. They harbour pests and disease and block air around the next sprouts.
- Pick a few from every plant Taking a handful from each plant every week spreads the harvest over the longest possible time.
- Finish with the sprout tops When the stem is bare, cut the leafy top. It cooks like spring greens and is one of the best bits of the plant.
Picking a few, or the whole stalk?
Pick as you go
The traditional way for a long harvest.
- Sprouts ripen in stages up the stem
- Fresh sprouts for weeks from one row
- Best for older, open-pollinated varieties
Harvest the whole stalk
One big picking, for an occasion or to free the bed.
- Cut the stem at the base when most sprouts are ready
- A whole stalk keeps a week or more in a cool shed
- Uniform modern varieties suit this best
Timing your harvest for Christmas
For sprouts on the Christmas table, choose a mid-season variety and look at the plants in early December. If the bottom sprouts are already full size, pick them now and keep the plant going; the next tier will be ready in time. If sprouts are still small, leave them: cold weather slows growth, but the buttons will firm up. Some gardeners pinch out the growing tip of the plant in early autumn so the sprouts all size up together, which is useful if you want one large picking.
Keep the plants standing firm through winter. Earth up around the stem and stake tall plants: a sprout plant rocked by wind produces loose, open sprouts. Netting keeps pigeons off the leaves, which they target when snow covers other food. Our guide to protecting plants from frost covers winter care on the plot.
Common mistakes
- Waiting too long. Large sprouts open up and turn bitter. Pick when firm, not when huge.
- Picking from the top. Upper sprouts are the youngest; start at the bottom.
- Harvesting before any frost. Early sprouts are fine, but the sweetest come after a cold snap.
- Handling frozen sprouts. Let them thaw on the plant first to avoid bruising.
- Leaving plants loose. Wind rock gives open, poor sprouts. Firm the soil and stake.
Frequently asked questions
How long do Brussels sprouts take to be ready?
Most varieties take 26–36 weeks from sowing to the first harvest, which is why they are sown in spring for an autumn and winter crop.
Should I wait until after a frost to pick sprouts?
You do not have to, but the flavour is sweeter and milder after one or two frosts.
Why are my sprouts loose and open?
Usually loose soil, wind rock, too much nitrogen or harvesting too late. Firm planting and staking help most.
Can you eat Brussels sprout leaves?
Yes. Young leaves and especially the sprout top at the end of the harvest cook like spring greens or kale.
A row of sprouts is a winter-long harvest when you pick little and often. Browse Brussels sprout seeds, more leafy brassicas and kale, see all vegetable seeds or the full seed shop, and explore the rest of our growing guides.
