The four bed crop rotation, and how to run it in a small patch

May 24, 2025

The four bed crop rotation, and how to run it in a small patch

If a bed that grew beautifully one year flops the next, the reason is usually sitting in the soil rather than in your watering can. Growing the same family in the same ground season after season strips out the same nutrients every time and lets the pests and diseases that specialise in that family build up quietly underneath, and rotation is the very old and very simple answer to both problems at once.

Why tomatoes are the usual offender

Tomatoes are greedy feeders, particularly on nitrogen and potassium, so a bed that has grown them hard for a season comes out the other end noticeably poorer than it went in. On top of that, the soil borne diseases that go after tomatoes sit in the ground over winter waiting for a host, and if you give them the same host in the same spot you've effectively kept feeding them. Move the tomatoes and you break the cycle without spraying anything.

The four groups

Split whatever you have into four, whether that's four beds, four corners of one bed, or four groups of pots. Each season everything shuffles along one place.

Group 1, legumes. Peas and beans. They fix nitrogen into the soil rather than stripping it, so they leave the ground better than they found it.
Group 2, leafy greens. Lettuce, spinach, silverbeet, the brassicas. These want the nitrogen the legumes just put there, so they follow on directly.
Group 3, fruiting crops. Tomatoes, capsicum, cucumber, zucchini, pumpkin. Hungry, and happy to go into ground that has been fed by the two groups ahead of them.
Group 4, root crops. Carrots, beetroot, onions, radish, turnips. They go last because they want the leftovers rather than rich ground, and a carrot in fresh manure forks every time.

Then it starts again with the legumes. You don't need a spreadsheet for this. A note on the back of a seed packet or a photo on your phone at the end of each season is honestly enough.

It works in pots too

No beds isn't a reason to skip it. Rotate between containers, or just move the planting position within one big bed. The only rule you're trying to keep is that the same plant family doesn't go back into the same soil two seasons running, and in a pot you have the extra option of simply tipping the mix out and starting fresh.

What it looks like when nobody rotates

Soil borne pests build up. Nematodes and the fungal wilts in particular, because they have been handed the same host on a plate.
Growth gets weaker every year. The same crop pulls the same nutrients out, so the deficiency compounds rather than evening out.
One bed thrives while another sulks for no reason you can see from the surface, which is the tell that it's a soil history problem rather than a one off.
Feeding stops fixing it. You can fertilise over the top for a while, and at some point the bed stops responding, and that's usually the season people give up on it.

Rotation is the low effort end of gardening. You do the thinking once, at the point where you're deciding what goes where, and then the rest of the season looks after itself. Everything you need to set it up sits in the garden centre, with the seed rack and the pelletised feed in the one spot.

Shop related products

D.T. Brown Seeds Lettuce All Year. For the leafy greens group.
D.T. Brown Zucchini Lebanese. For the fruiting group.
D.T. Brown Seeds Carrot All Season. For the root group.
Neutrog Rapid Raiser 20kg. A pelletised organic feed for bringing a tired bed back before you replant it.
Brunnings Easy Wetta Potting Mix 70L. For anyone running the rotation in containers.

Did you know we also stock pea and bean seed in the shop that isn't listed on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The rest of it is in the garden centre collection, and the fertiliser range is under Neutrog.

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The four bed crop rotation, and how to run it in a small patch