Fungi are not vegetables botanically; they're a separate kingdom of organisms altogether. Mushrooms lack chlorophyll, roots and seeds that define plants, yet they behave like vegetables in the kitchen—offering umami, texture and nutrition. Understanding this distinction helps you cook and source them better.
Why mushrooms aren’t plants, and what they actually are
When you bite into a gourmet mushroom, you’re eating the fruiting body of a fungus—the part that emerges above ground. Fungi belong to their own biological kingdom, separate from plants, animals and bacteria. They don’t photosynthesise; they break down organic matter and absorb nutrients instead. This fundamental difference shapes everything about how they grow, taste and behave in cooking.
The mushroom itself—what we harvest and cook—is just the visible fruiting structure. Beneath the soil or substrate sits the mycelium, a network of thread-like filaments that does the real work of decomposing material and converting it into food. When conditions are right (moisture, temperature, oxygen), the mycelium produces mushrooms the way a tree produces fruit. The fruiting body releases spores, completing the life cycle. This is entirely different from how vegetables grow.
What makes mushrooms behave like vegetables in cooking
In the kitchen, mushrooms function almost identically to vegetables. They’re savoury, can be roasted, sautéed, grilled or pickled, add depth and umami to dishes, and pair naturally with herbs, stocks and other ingredients the way root vegetables or brassicas do. You’ll find them in restaurant menus and markets alongside courgettes and peppers, not in a separate category. This practical equivalence is why most chefs and cooks treat mushrooms as vegetables, regardless of their actual biology.
The confusion is understandable and historically rooted. For centuries, nobody had the tools to know fungi were anything other than strange plants. Now we know better scientifically, but culinarily and nutritionally, the classification is beside the point. What matters is what mushrooms taste like, how they cook, what texture they give a dish, and what flavour compounds they carry. A sautéed oyster mushroom behaves more like a vegetable than a protein, even though it contains modest amounts of amino acids. Most home cooks and professional kitchens simply slot them into the vegetable section, and that works fine.
How does this distinction affect the way you source and grow mushrooms
At Adi’s Urban Mushrooms in West Norwood, I grow gourmet mushrooms on purpose-built substrate, not in soil the way vegetables are cultivated. I control the entire growing environment—humidity, air exchange, temperature, light—rather than relying on seasons or outdoor conditions. This gives me consistency and the ability to produce year-round. Because fungi break down organic matter rather than drawing nutrients from soil, I can use composted straw, hardwood sawdust or agricultural waste as a growing medium, which is both more sustainable and more suited to small-batch urban production than land-intensive vegetable farming.
This also changes how I think about sourcing and transparency. When I sell fresh mushrooms at West Norwood Feast or to local restaurants, I can name exactly what substrate they were grown on, how long they took to fruit, and what the growing environment was. There are no soil conditions or regional weather variations to account for—just the controlled inputs I chose. For customers and chefs, this means predictability and traceability. It also means I can scale production in a kitchen-sized space in South London, something impossible with traditional vegetable farming. The non-plant nature of mushrooms is actually an advantage for local, transparent food production.
Does the botanical difference change the nutritional or flavour profile
The fact that mushrooms are fungi doesn’t make them more or less nutritious than vegetables; it just means they deliver nutrition differently. Mushrooms are rich in B vitamins (especially B12 in some species, though in small amounts), contain compounds like ergothioneine and polysaccharides that vegetables don’t, and offer a savoury, umami depth that comes from free glutamates—the same compound in parmesan or ripe tomatoes. They’re low in calories, absorb flavours readily, and add a satisfying meaty texture when cooked, which is why they work as a centrepiece or base for vegetarian cooking.
In terms of flavour, the kingdom distinction is almost irrelevant. What matters is the species. A king oyster mushroom tastes entirely different from a shiitake or a button mushroom because of their distinct genetic makeup and the way they metabolise compounds in the substrate. When I work with restaurants or teach cultivation workshops at Community Mycology Lab in Brixton, cooks want to know the variety, the harvest date, and how to cook it—not whether it’s technically a fungus. The taxonomy is scientifically interesting but culinarily secondary to species, freshness and technique.
Practical takeaway: how to think about mushrooms when you’re buying or cooking
For your kitchen, treat mushrooms as vegetables. Buy them fresh or dried, store them the way you’d store other produce, and cook them using vegetable techniques. They fit into salads, stir-fries, stews, and grain bowls exactly as courgettes or mushrooms would—because functionally, that’s what they are. The scientific reality (that they’re fungi, not plants) is fascinating, but it doesn’t change how you use them.
If you’re interested in where your mushrooms come from, look for growers who can tell you the species, the substrate, and the harvest date. At markets like West Norwood Feast or through foraging walks with the South London Mushroom Club, you’ll find producers who track these details because they matter for flavour and quality. Whether they’re technically vegetables or fungi becomes a trivia point once you taste the difference between a commercially grown button mushroom and a fresh, locally grown gourmet variety. That difference is real, botanical classification aside.