Heavy, medium and light feeders: the nutrient table for your raised bed

Frau Schneider, my neighbour here in Berikon, grew tomatoes in the same corner of her raised bed two years in a row. First year: glorious. Second year: half the crop, pale, puny. She dumped 30 francs of fresh compost in and figured she'd got the watering wrong. She hadn't. The corner was simply eaten bare.

That's not a disease and it's not bad luck. It's feeder logic, and luckily it's easy to learn.

What "feeder" actually means

Gardeners sort vegetables into three groups depending on how much they pull out of the soil. In German garden lore these are the Zehrer — the eaters:

• Heavy feeders (Starkzehrer) — the big eaters. Fast growth, lots of leaf, lots of fruit. Tomato, zucchini and pumpkin are the classics.
• Medium feeders (Mittelzehrer) — the solid middle. They want something, but they don't overdo it.
• Light feeders (Schwachzehrer) — the modest ones. They get by on little, ideal for year three when the soil is already tired.

The table

Around 25 common crops, sorted by appetite. Print it, pin it to the shed, done:

Heavy feeders (Starkzehrer)	Medium feeders (Mittelzehrer)	Light feeders (Schwachzehrer)
Tomato	Lettuce	Radish
Zucchini	Chard	Pea
Cucumber	Kohlrabi	Bean
Pumpkin	Fennel	Lamb's lettuce
Pepper	Onion	Rocket
Aubergine	Carrot	Herbs (parsley, dill, thyme)
Cabbage & broccoli	Beetroot	Garlic
Potato	Spinach	Cress
Celeriac	Pak choi
Leek	Red beet

The lines aren't set in stone — a well-fed carrot forgives the odd heavy-feeder neighbour. But as a rule of thumb for planning, the table holds up.

Why this matters for crop rotation

Here the table turns from nice to useful. A raised bed is brimming with strength in its first year — freshly filled, everything in it. How that fill is built up is in Filling a raised bed: the layers. That strength runs down year after year. The clever order:

• Year 1: heavy feeders. The fresh soil can take a lot, so give the hungry ones the front seat — tomato, zucchini, pumpkin.
• Year 2: medium feeders. Lettuce, onion, carrot. They take what's left without complaining.
• Year 3: light feeders and legumes. Radish, herbs — and above all beans and peas.

Frau Schneider's mistake was the exact opposite: heavy feeder on heavy feeder, same spot, second year. The second round finds nothing and disappoints. Two big eaters back to back on the same patch almost always goes wrong.

Beans and peas are the repair crew

The nicest trick, saved for last. Beans and peas aren't just modest — they actually give something back. Their roots carry little nodules full of bacteria that pull nitrogen out of the air and put it into the soil. So they fertilise for free while they grow.

That's why they sit at the end of the rotation: they patch the ground up for the next round of heavy feeders. When I've got a tired patch of bed, in goes a season of beans, and the year after everything grows there again.

What beans and peas don't replace is targeted feeding mid-season, when a heavy feeder runs hungry. When that becomes necessary and how you spot it, I've written up in Feeding in June.

What Erntezeit does with this

You don't have to memorise any of it. You tell me what you want in your bed, and I sort the feeders in the background — which crops compete for nutrients, and in what order across the years they cause the least trouble. When you plan again next year, I still remember what stood where, and I suggest the rotation that fits. Free for one bed.

Start a plan for your bed →

Frau Schneider's tomato corner, by the way, is a bean patch this year. Next year she'll wonder how the soil got so good again.

🦔 Stachi