Myths About Growing Broccoli in Scotland

“Broccoli is broccoli, so any packet will give you heads like the supermarket ones”

They are two different crops sold under one name. Calabrese and broccoli are genuinely distinct, often muddled up, with both widely called broccoli. The large green head you buy in a shop is calabrese. Sprouting broccoli produces small clusters of purple or white buds on the tips of long leafy stems instead, and calabrese is confusingly called broccoli in supermarkets and recipes.

Our read This is not a naming quibble, it is a whole season. Calabrese is sown in spring and cut three or four months later, from July to October. Sprouting broccoli can take four to ten months to start cropping and is picked from June right through to the following March. Buy the wrong packet and you have committed a bed for most of a year expecting a summer crop.

What to do: Read the packet for the actual crop rather than the word broccoli. If you want the supermarket head, look for calabrese and sow in spring. If you want purple stems through the hungry gap, that is sprouting broccoli and it needs the ground for far longer.

In Scotland: Sprouting broccoli earns its long occupation here in a way it does not further south, because it crops from late winter into spring when a Scottish plot has almost nothing else standing. The trade is real though: that is most of a year of bed space for one hungry-gap crop.

“Once you've cut the main head the broccoli plant is finished”

Cutting the central head is what triggers the second crop rather than ending the first. On calabrese, further smaller heads form on side-shoots after the main head is cut, extending the harvest for up to eight weeks. Pulling the plant at that point throws away two months of picking.

Our read The mistake makes sense if you have only ever seen calabrese in a shop, where it arrives as a single head with no plant attached. Nothing about the supermarket version suggests there is more to come.

What to do: Cut the central head cleanly while the buds are still tight and leave the plant standing. Keep watering and picking the side shoots as they size up, and only clear the bed once they stop coming.

“Lime the ground and clubroot is dealt with”

Liming helps and it does not cure. Club root is reduced, but not eliminated, by raising soil pH. The reason is the resting spores, which can contaminate soil for up to twenty years, and no amount of lime reaches them. Liming makes conditions less favourable rather than clearing the ground.

Our read Treat it as management rather than a cure, because the difference matters for planning. Ground that has had clubroot has it for the rest of your gardening life, and every brassica you put there is a decision rather than a default.

What to do: Lime to raise pH and improve drainage at the same time, since the two are usually paired and raised beds are the usual answer. Raise plants in modules so they go out with a decent root system already made, and lengthen the rotation as far as your plot allows.

In Scotland: This is close to a worst case for us. Clubroot thrives in wet ground at low pH, and naturally acidic, poorly drained soil describes a great deal of Scotland. Drainage is often the bigger lever here, not the lime.

“Grow a clubroot-resistant variety and you can forget about clubroot”

The varieties on offer carry some degree of resistance rather than immunity. A number are listed, with careful wording, and partial resistance behaves differently from immunity: a resistant plant in badly infected ground can still be damaged, particularly where the pressure is high and the drainage poor.

What to do: Use them as one layer alongside liming, drainage and rotation, not as a substitute. Where you have clubroot, resistant varieties are worth the money; where you do not, they buy nothing that ordinary rotation does not.

In Scotland: The same pattern shows up in Scottish raspberry breeding, where aphid resistance bred into the Glen varieties has been eroding. Resistance is a moving target rather than a permanent fix.

“A sacrificial trap crop will draw pests away and protect your main crop”

The attraction is real but the protection does not follow. In trials using turnip rape as a border around cauliflower, the trap crop took over nine tenths of all flea beetle feeding damage, yet the reduction in damage to the cauliflower itself was small enough to be indistinguishable from chance, and buying even that meant giving up roughly half the growing space.

What to do: On a garden-sized plot, skip it. If you do try one, avoid Chinese cabbage: it pulls cabbage root fly powerfully but the fly breeds on it perfectly well, so the trap becomes a nursery and next season starts worse than this one did.

“Beans and peas fix nitrogen that feeds the crops growing beside them”

Legumes genuinely do fix nitrogen. What they do not do is hand much of it to a neighbour while both are still growing: transfer between living plants in the same season is small and hard to pin down. The substantial nitrogen, tens of kilos per hectare from clover and beans, arrives when the legume dies and breaks down.

Our read That makes it a rotation benefit wearing a companion's clothes. The effect is real, it just arrives a season later than the folklore claims.

What to do: Follow peas and beans with a hungry leafy crop the next season, rather than expecting this year's cabbage to be fed by the beans growing next to it. Leave the roots in the ground when you clear the plants.