How to build a lasagne garden bed, layer by layer

What a lasagne bed actually is

A lasagne bed is a garden bed you build on top of the ground instead of digging one out of it, and the name is just about the layers, because you stack brown material and green material alternately the way you would stack pasta and sauce. It all breaks down in place, so you are composting exactly where the plants are going to grow rather than composting in a heap in the corner and then barrowing it across the yard.

It is the method I point people at when they have got a patch of lawn or a strip of hard compacted dirt down the side of the house and no particular desire to spend a weekend on the end of a mattock. You are not fixing the ground underneath. You are building new ground on top of it and letting the worms deal with the join.

The layers, in the order they go down

1. Cardboard or newspaper, soaked. Plain brown cardboard with the tape and the labels pulled off, laid so the sheets overlap by a good hand span, then wet right through. This is the layer that kills the grass, and if you skip the overlap the couch will find the gap and come through it.
2. A brown layer. Straw, dry leaves, sugar cane, shredded paper. Carbon, in other words, and it wants to be the thicker of the two.
3. A green layer. Grass clippings, kitchen scraps, aged manure, a scatter of blood and bone. This is the nitrogen that gets the whole thing breaking down rather than just sitting there.
4. Keep alternating. Brown, green, brown, green, and water each layer as it goes on so the whole stack is damp rather than just the top of it.
5. Finish with compost or a bagged garden soil. This is the bit you actually plant into, so it needs to be something a seedling can get its roots into straight away.
6. Mulch the top. It holds the moisture in and it stops the whole thing crusting over.

Build it higher than you want it to end up, because it sinks a long way as it breaks down and everyone is surprised by how much.

How long to leave it

If you have got the patience, leave it a few weeks before you plant, so the layers knit together and the heat comes out of the green material. If you have not got the patience, and honestly most of us have not, pull a hole in the top layer, fill the hole with bagged soil or compost and plant into that pocket while the rest of the bed keeps cooking underneath. That works, and it is what I do.

What to plant in it

Anything that likes rich soil and does not mind a bed that is still settling. Leafy greens are the easiest start because they are shallow rooted and they do not care that the layer under them is still straw. Tomatoes, cucumbers, zucchini and beans all go well once the bed has had a bit of time. Root crops are the one I would hold off on for the first season, because carrots pushing down through half broken down straw fork and twist and you end up disappointed with something that was never the carrot's fault.

Why it is worth the effort

Digging a bed out of compacted ground is most of a Saturday, and then you are sore on the Sunday, and the ground you turned over is the same ground it always was. A lasagne bed takes an hour or so of stacking, most of the material is stuff you would otherwise be getting rid of, and the bed gets better every year instead of going back to how it was. Your Saturday is worth something, and that is a fair chunk of one.

Shop related products

• Martins Organic Sugar Cane Bale 11kg. Brown layer material by the bale, and one bale goes a surprising way.
• Brunnings Blood and Bone Based Fertiliser 5kg. A scatter through the green layers, for the nitrogen.
• Brunnings Garden Compost with Seaweed 25L. The planting layer on top, or the pocket you plant into if you are not waiting.
• Easy Wetta Garden Mulch 50L. The lid on the whole thing, so it does not dry out and crust.

Did you know we also stock pea straw and lucerne bales, mushroom compost, the 90L mega mulch block and bagged gypsum for the clay underneath. Not all of it is on the website, so give us a ring on (08) 8536 4333 to check what is on the shelf.

The bagged soil, the manures, the bales and the mulch all sit together in the garden centre, and the online range is in garden products if you want to work out the quantities first.

A bed this size is a lot of bags, so it is worth knowing we deliver. Strathalbyn is $5 and the wider run is $10, Tuesdays and Thursdays, and the towns are listed on the local delivery page.

Read next

• What is the cardboard weed barrier method?
• Compost activators, and whether your heap needs one
• How to turn compacted soil without wrecking your back

I would rather stack a bed than dig one, and I am not going to pretend that is a decision about soil science.

Cheers,
Candeece