Planting Out Early Brassicas: Cabbages, Cauliflowers and More

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Brassicas. The cabbage family. Now there’s a group of vegetables that don’t get nearly enough credit if you ask me. Everyone’s banging on about tomatoes and courgettes and all the glamorous summer stuff, but nobody’s out there making TikToks about cabbages, are they? And that’s a shame because a properly grown cabbage is a thing of beauty. I’ll die on that hill. Come at me.

Now planting out early brassicas — your cabbages, cauliflowers, broccoli, maybe some early calabrese — is one of those jobs that sounds simple but has a few tricks to it. Get it right and you’ll be harvesting gorgeous heads of cabbage while everyone else is still waiting for their tomatoes to ripen. Get it wrong and you’ll end up with a row of sad, floppy plants that the pigeons have had for breakfast. I’ve had both outcomes, sometimes in the same year on the same bed. That’s gardening for you.

When to Plant Out

Timing with brassicas is everything. Too early and a late frost will knock them sideways. Too late and they won’t have enough cool weather to form proper heads before it gets too warm. For early varieties — and that’s what we’re talking about here — I aim to plant out from about mid-April onwards, depending on the weather. If it’s been a mild spring, sometimes I’ll chance it a bit earlier. If it’s been rubbish, I hold off.

The plants should be about 4-6 inches tall with a good set of true leaves. Not the little round seed leaves, the proper ones that look like actual cabbage leaves. If they’re still tiny and spindly, give them another week or two inside. There’s no rush. Well, there is a bit of a rush, but pushing them out before they’re ready just means they’ll sit there doing nothing for ages and you’ll feel like a bad parent. Ask me how I know.

I remember one year I got dead excited because we’d had this lovely warm spell in March. Stuck all my cabbages out, all twenty of them, feeling very pleased with myself. Then we got frost. Not just a light frost either — a proper hard one, minus four or something daft. Went up the next morning and they were all drooping like they’d been on a heavy night out. Lost the lot. JB didn’t say a word, which was worse than if he’d taken the mick. That silent look of sympathy from someone who told you to wait — devastating, that is.

Preparing the Planting Spot

Brassicas are hungry plants. Properly hungry. They want rich, firm soil with a good amount of nitrogen. Now here’s where most people go wrong — they plant brassicas in freshly dug, loose soil. Brassicas actually prefer firm ground. Sounds weird, I know. But their roots need something solid to grip onto, especially once the plants get big and top-heavy. If the soil’s too loose, a strong wind will rock them about and you’ll end up with what’s called “blown” plants — they go all loose in the head and don’t form properly.

So ideally, you want to prep the bed a few weeks before planting. Add your compost or manure, fork it in, and then leave it to settle. Some people even tread it down gently with their boots. I do — and yes, I know that sounds mad after I’ve just spent ages getting it nice and loose for the summer beds, but brassicas are different. They’re contrary. Like most of me family.

Also — and this is important — check your soil pH if you can. Brassicas like it slightly alkaline, around 6.5 to 7.5. If your soil is acidic, add a handful of garden lime when you’re prepping the bed. This isn’t just about growth either — club root, which is the absolute worst disease brassicas can get, thrives in acidic soil. Adding lime helps prevent it. And trust us, you do NOT want club root. Once it’s in your soil, it can stay there for twenty years. Twenty years! Ronny’s had it on one of his beds and he’s been dealing with it for as long as I’ve known him. Poor bloke.

How to Actually Plant Them

Right, the actual planting. Make a hole with a dibber or a trowel — deep enough that the seedling goes in up to its first set of true leaves. Brassicas can handle being planted a bit deep; they’ll actually grow extra roots from the buried stem, which makes them more stable. Push the soil firmly around the base. And I mean firmly — really press it in with your knuckles. Give each plant a gentle tug afterwards. If it comes out easily, you haven’t firmed it enough. Do it again.

Spacing depends on what you’re growing. Cabbages want about 45cm apart. Cauliflowers need a bit more — 60cm ideally, because they’re divas and they need their personal space. Broccoli and calabrese are similar to cauliflowers. Don’t be tempted to squeeze them in closer. I know it’s tempting when you’ve got limited space, but overcrowded brassicas just end up competing with each other and you get a load of small, mediocre heads instead of a few proper good ones.

After planting, give them a really good water. Not a sprinkle — a proper soaking. Then water them regularly for the first couple of weeks until they’ve settled in. After that they’re pretty tough and can usually cope with normal rainfall, unless it’s really dry.

The Pigeon Problem

Right, let’s talk about the elephant in the room. Or rather, the pigeon on the cabbage. Because if you plant brassicas without protection, the pigeons will have them. Not might have them. WILL have them. They love brassicas more than anything. It’s like an all-you-can-eat buffet for them. You’ll go up one morning and your beautiful cabbages will be nothing but stalks with a smug pigeon sitting on the fence looking very well fed.

The solution is netting. Get yourself some proper brassica netting — the stuff with the small holes, not the big bird netting which pigeons can just walk through (don’t ask me how I found that out). You can either drape it over hoops made from blue water pipe — cheap as chips from the plumbers’ merchant — or build a cage from timber and netting if you’re feeling fancy.

The key is to make sure the netting doesn’t rest on the plants. Leave a good gap. If the netting is touching the leaves, the pigeons will just stand on top and peck through it. Clever little blighters, they are. I’ve seen them do it. Stood there watching, absolutely livid, while a pigeon stood on my netting and systematically ate every leaf it could reach through the mesh. That was the day I invested in proper hoops.

Keeping Them Growing Strong

Once your brassicas are in and netted, the main jobs are watering, feeding, and keeping an eye out for problems. For feeding, a nitrogen-rich feed every couple of weeks works well. I use liquid seaweed mostly — it’s organic, it’s not too strong, and the plants seem to love it. Audrey uses nettle tea that she makes in a big bucket by the shed. It works brilliantly but it absolutely stinks. Like, properly stinks. I can smell it from three plots away. She doesn’t seem to notice anymore. Or maybe she just doesn’t care. Either way, it grows cracking cabbages.

Watch out for caterpillars. The cabbage white butterfly is pretty, I’ll give it that, but its caterpillars are absolute demolition machines. Check the undersides of leaves regularly for little clusters of yellow eggs. Squash them. Sorry, but it’s them or your cabbages. If you spot caterpillars already munching away, pick them off by hand. It’s grim but it works. Some people use Bt spray (Bacillus thuringiensis) which is an organic caterpillar treatment, and that works well too if you’re squeamish about the hand-picking.

What About Slugs?

Ah, slugs. My old enemies. They’re not as big a problem for established brassicas as they are for tender stuff like lettuce, but they’ll have a go at young transplants, especially in the first week or two when the stems are still soft. I use a mix of methods — organic slug pellets (the ferric phosphate ones, not the old metaldehyde ones which are terrible for wildlife), beer traps, and crushed eggshells around the base of each plant.

Do any of these actually work consistently? Honestly? Not really. The beer traps catch some. The eggshells might slow a few down. The pellets probably do the most. But the real secret is just getting your plants established quickly so they can outgrow the slug damage. A strong, healthy brassica plant can cope with a bit of nibbling. A weak, newly planted one can’t. So look after them in those first couple of weeks and you’ll be fine.

Harvesting Your Early Brassicas

Early cabbages can be ready from about 10-14 weeks after planting out. You’ll know they’re ready when the head feels firm and solid when you give it a squeeze. Don’t leave them too long — if the head starts to crack or split, it’s been in too long. Cut them with a sharp knife just below the head, leaving the stalk in the ground. Here’s a bonus trick — cut a shallow cross in the top of the stalk, and many varieties will produce a few smaller secondary heads. Free bonus cabbages! Doesn’t always work but when it does, it’s brilliant.

Cauliflower is trickier because you need to catch it at just the right moment. When the curd (that’s the white bit) is about the size of a dinner plate and still nice and tight, that’s your window. Leave it a day too long and it starts to go loose and “ricey.” I’ve missed the window more times than I’ve hit it, to be honest. Cauliflower is the diva of the brassica world. Beautiful when it goes right, absolutely maddening when it doesn’t.

Calabrese (what most people call broccoli) is more forgiving — cut the main head when it’s nice and tight, then the plant will throw out loads of smaller side shoots for weeks afterwards. Dead easy and probably the best value brassica for a small plot.

Look after yourselves. Take good care. 🌱