Inspired by GrowVeg. This guide draws on the "Growing Broccoli from Sowing to Harvest" video by GrowVeg, a UK-based gardening channel run by Ben Vanheems with over a million subscribers. The video covers both calabrese and purple sprouting types with clear, practical demonstrations.
1. Choose the right type for what you want
Calabrese (the large domed green head often labelled simply as broccoli in shops) is a summer and autumn crop. Sow in spring, harvest the same year. One good central head per plant, though side shoots follow once you've cut it. It's the faster, simpler option.
Purple sprouting broccoli is a different vegetable. It overwinters and produces in late winter to early spring - a useful time when little else is ready in the garden. It takes around ten months from seed to harvest, so timing needs a bit of forward planning. If you want both, grow both. They don't compete for the same season.
2. Sow calabrese indoors in April
Calabrese does best sown in modules or small pots rather than direct into the ground, partly because it dislikes root disturbance. Sow one or two seeds per module in late March or April, about 1 cm deep. A windowsill or unheated greenhouse at around 15-18°C is fine.
Thin to the stronger seedling after germination. Calabrese can be sown directly outside from May once the ground has warmed, but module-raised plants tend to establish more reliably. In a good year, direct sowing works well in East Kent's relatively mild spring conditions.
3. Sow purple sprouting in May or June
Purple sprouting broccoli is sown later - from mid-May through to mid-June. Same approach: modules or small pots. It grows through summer and autumn, then overwinters to produce the following late winter and spring. Don't sow too early, or you end up with a very large plant that may struggle to support itself through the winter months.
4. Pot on and harden off before planting out
Once seedlings are about 10-12 cm tall with good root growth, they're ready to move on. If you've been growing them under cover, spend a week or so hardening off first: move plants outside during the day, bring back in at night. This matters especially for early-sown plants going into unpredictable spring weather. A few days of that transition makes a real difference to how well they settle in.
5. Plant with plenty of space
Both types need more room than most people allow. Calabrese wants at least 45 cm between plants and rows. Purple sprouting is bigger still and needs 60 cm or so - these become substantial plants over the season.
Firm the soil well around the roots when planting. Broccoli needs very firm planting. Press the soil down hard after settling the rootball in and water in well. In Kent's sometimes breezy conditions, that firm planting is worth doing properly. A loosely planted brassica rocks in the wind, loosens at the roots, and develops poorly.
6. Keep plants anchored as they grow
Purple sprouting varieties in particular get tall and can rock in autumn and winter winds, which loosens roots and stunts development. Earth up around the base as the season progresses, and stake if needed. A cane and garden twine works for most plants; larger specimens may need something sturdier before the stormy months arrive.
7. Water consistently and net against pests
Broccoli is a brassica, which means pigeons and cabbage white butterflies will find it. Netting is the most reliable protection: fine mesh butterfly netting from planting out through to harvest, supported on hoops so caterpillars can't reach leaves through the sides. Set it up properly once rather than replacing stripped plants.
Water regularly, especially during dry spells while heads are forming. Consistent moisture produces better-quality heads and reduces the risk of plants bolting. East Kent can have dry patches through summer, so keep an eye on it.
8. Harvest before the flowers open
This is the timing that matters most. Calabrese heads should be cut when the florets are tightly closed and the head is a deep, even green. Leave it a day too long in warm weather and the florets open into yellow flowers - still edible, but not what you grew it for.
Cut the central head with a clean angled cut. Side shoots follow and can be harvested over several weeks. For purple sprouting broccoli, harvest when the shoots are about pencil-thickness with tight, dark buds. Pick regularly to keep the plant producing through the season.
When to call a handyman
The growing itself is all gardening, but if you're putting in raised beds, setting up a permanent brassica cage with a proper frame, or preparing ground that needs work before you start, Richard can help with that. Raised bed construction and garden bed preparation are regular jobs in and around Sandwich and the surrounding villages.
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