How to grow broccoli and cabbage, and when to plant them

February 15, 2026

Broccoli and cabbage are two of the easiest things to grow over the cooler months here, and most of the trouble people have with them comes down to planting them at the wrong time of year, because they're cool weather crops and they'd much rather grow slowly through autumn and winter than be pushed along in the heat.

When to plant them

Around Strathalbyn I'd sow the seed from late summer into early autumn, or put seedlings in from about February through to April, so they've got some size on them before the cold sets in and they can form their heads through winter and into spring. Planted too early they tend to bolt to flower in the last of the heat, and planted too late they sit in cold soil and barely move.

Getting the bed ready

They're hungry plants, so dig a good amount of compost or well rotted manure through the bed a couple of weeks before planting, along with a handful of a complete fertiliser like blood and bone. They don't like acid soil either, so if you know your soil runs acidic it's worth testing it and adding a bit of garden lime well ahead of planting, because it takes time to work.

Spacing

Give each plant about 45 to 60cm, which looks like far too much room when the seedlings go in and about right by the time they're fully grown. Crowded brassicas compete for water and food and you end up with small heads, and the air doesn't move between them, which is when the leaves start to rot in a wet winter.

Water and mulch

What they want is steady moisture, so a deep soak once or twice a week beats a sprinkle every evening. A layer of sugar cane or pea straw over the bed keeps the soil evenly damp in between. Cabbages that dry right out and then get a heavy drink are the ones that split, so evenness matters more than the amount.

Pests

The cabbage white butterfly lays eggs on the undersides of the leaves, and the green caterpillars can strip a young plant fast, so check under the leaves every few days and squash the eggs and caterpillars you find. Snails and slugs love the young seedlings too, especially after rain. If you do reach for a spray, check that the label lists caterpillars and vegetables and follow the withholding period before you pick.

Picking

Cut broccoli while the head is tight and green, before any of the little buds start opening into yellow flowers, and leave the plant in the ground, because most broccoli will keep sending up smaller side shoots for weeks afterwards. Cabbages are ready when the head feels firm and solid when you squeeze it.

Shop related products

Brunnings Seed Raising Mix 5L. For starting broccoli and cabbage from seed in trays.
Brunnings Blood & Bone Based Fertiliser 5kg. Dug through the bed before planting.
Seamungus 500g. A pelletised seaweed and manure feed for through the season.
Martins Organic Sugar Cane Bale 11KG. Mulch to keep the soil evenly damp.

Did you know we also stock broccoli and cabbage seed along with snail and slug pellets in the shop, and they aren't on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

Everything else for the veggie patch is in our garden centre, and if you're not sure what to plant when, just ask us when you're in.