Fungi: The Quiet Architecture Underground

Anyone who sees a plant sees only half of it

What stands above ground is familiar to everyone. Leaves, stem, blossom, fruit. What happens beneath is the other half – and probably the more important one.

In healthy soil, fungi weave a network so fine and far-reaching that it remains hard to picture: in a single square metre there are often several kilometres of delicate fungal threads, called hyphae. They connect trees with trees, shrubs with perennials, individual plants with their neighbours. They exchange water, nutrients, signalling substances. They warn one another about pests. They share.

So anyone seeing a plant – an olive tree on a rooftop terrace, a Strelitzia in a living room, an Areca in a lobby – sees only the visible part of a double being. The invisible part is just as alive, often just as old, sometimes older.

An old acquaintance

Fungi and plants have lived in partnership for around 400 million years. To put it precisely: without fungi, plants would never have left water for land. The first plants had no real roots – the fungi were their roots. Only later did plants develop their own root systems, while keeping the fungal partnership as a foundation.

Today, more than 90 percent of all land plants live in close partnership with specialised soil fungi. The plant gives the fungus sugar produced through photosynthesis. The fungus gives the plant water, phosphorus, nitrogen, minerals from distant soil layers. An honest exchange that works without money.

On a rooftop terrace with limited substrate volume – say a 30 cm planter – this partnership is even essential for survival. A plant connected to fungi has effectively a 10- to 100-fold larger root system than without. It manages with half the water, survives heatwaves better, blooms more abundantly, lasts longer.

What we do – and what we do not

The main mistake in many greenings: synthetic fertilisers and chemical care destroy the fungal partnership. The plant receives water and nutrients directly and no longer needs the fungus. But it will no longer be able to do anything by itself. When the fertiliser stops, it collapses.

We take the opposite path. For every exclusive project, we inoculate the substrate with selected symbiosis fungi strains before placing the plant. The strains are regional and matched to the specific plant species – an olive tree needs different partners than a Phalaenopsis orchid. Then we keep chemistry away. Whatever comes, comes from compost, biochar, organic substrates, occasionally effective microorganisms.

What you get from this: a greening that does not depend on us but becomes self-sustaining. Plants that are stronger after three to five years than on the day they were planted. An atmosphere that does not look managed but grown.

From edible mushroom to soil fungus

Anyone who knows fungi only from the plate – porcini, chanterelles, champignons – sees a tiny selection. These edible mushrooms are the fruiting bodies. The actual organism, the mycelium, lies in the soil, often invisible for years, sometimes extending across kilometres. The largest known fungus in the world stands in Oregon, covers more than two square kilometres and is presumably several thousand years old. It is the giant nobody thinks about.

In exclusive greening we do not work with edible mushrooms but with soil fungi that accompany roots symbiotically. They form no visible caps. They do their work in concealment. But without them there would be no vital plants – on no rooftop terrace, in no interior, in no garden.

What you can do yourself

If you have an existing greening and want to strengthen the fungal life within it:

1. No synthetic fertilisers. They are the fastest poison for soil fungi.
2. Regular compost. Mature compost feeds fungi and the entire soil life.
3. Mulch instead of hoeing. Fungal networks live in the upper 20 cm. Anyone working there tears them apart.
4. Soil rest in winter. Let the soil regenerate undisturbed.
5. For new plantings: inoculate. A small addition of symbiosis fungi at the root ball changes later growth dramatically.

Anyone planning an exclusive project cannot avoid this question: should the greening look quick or live long-term? Fungi are the answer to the second.