Foraging wild plants: the ground rules

Safe identification is based on a combination of features. Every single feature – toothed leaves, white umbrella-shaped flowers, garlic smell, parallel leaf veins – occurs in several plants, including poisonous ones. Only when leaf shape, leaf arrangement, stem, smell, flower or fruit, habitat and season all fit together does the identification become clear. That is why plants are best learnt over a whole season, from first shoots to fruit.

Just as important is knowing the dangerous look-alike. Anyone wanting to collect wild garlic must know lily of the valley and autumn crocus; anyone collecting plantain must know autumn crocus too; anyone wanting to collect umbellifers such as wild carrot must be able to rule out the deadly hemlocks reliably. Umbellifers are therefore completely off limits for beginners. In this atlas we only describe plants that can be told apart well by a few clear features.

The "universal edibility test" from the US manual FM 3-05.70 works with smelling, skin contact, lip and tongue contact and then small tastes with waiting periods. It is based on the assumption that toxicity shows early through irritation or nausea. That is exactly what is not true for the most dangerous plants of Central Europe: hemlock, autumn crocus or yew can be deadly in small amounts, and some poisonings only show after hours. So here the test is not protection but a risk.

The site also decides whether a correctly identified plant is harmless. Plants take up heavy metals, sprays, fertiliser and exhaust from soil, water and air. So you do not collect along roads, railway embankments, field edges, industrial sites, contaminated land and polluted water – washing does not remove what is inside the plant. Dog paths and game trails are not good collecting spots either, because of faeces and germs.

Order helps while collecting: each species goes into its own bag. That way no stray leaf that you overlooked while picking can get mixed in. At home or in camp you spread the harvest on a light surface and check leaf by leaf once more. You keep a sample of the plant until it is clear that everyone tolerated it well – in an emergency it helps with treatment.

Even a reliably identified, edible plant can occasionally cause problems: allergies, intolerances or interactions with medicines. That is why you eat anything new in a small portion first and wait a day. This is a tolerance check for a known plant – something completely different from trying to classify an unknown plant as non-poisonous by tasting it.

If plant poisoning is suspected, time counts. Signs can be nausea, vomiting, diarrhoea, stomach cramps, dizziness, tingling in the mouth, racing heart, confusion or breathing problems – sometimes only hours after eating. Then call 112 (in Austria also 144) or a poison information centre; in Austria you reach the Poison Information Centre on +43 1 406 43 43, in Germany there are regional poison information centres. Do not induce vomiting and do not give milk. Bring plant remains.

Fox tapeworm is a small parasite whose eggs get into the environment with the faeces of foxes – and also dogs and cats. Whether it is actually transmitted via forest berries or herbs is, according to the Robert Koch Institute, not fully clarified, and the risk is considered low. The disease, however, is serious. So you wash low-growing harvest thoroughly and preferably cook it. Heat kills the eggs, normal freezing does not. Washing your hands after collecting is part of it.

This atlas deliberately does not cover fungi. Many deadly mushrooms look confusingly similar to edible ones, and identification needs real expertise. Children should learn not to put anything that grows outdoors into their mouth without an adult – not even berries.

Wild plants are a good supplement when supplies run short or you are outdoors for a long time: they provide vitamins, minerals and variety. Leafy plants are no good as a main food because they contain very little energy. Anyone who collects greens for hours may burn more calories doing so than they take in. Energy comes rather from nuts, seeds and starchy rhizomes – and those are only available at certain times of year.

In a genuine emergency in the wild, protection from cold and wet comes first, then water, then getting help or being found. A healthy person can manage without food for some time, but only briefly without water and warmth. Looking for food only becomes important when the situation lasts longer. Legally: in Germany § 39 of the Federal Nature Conservation Act generally allows collecting small amounts for your own use outside protected areas; in Austria state laws regulate this. Protected species and protected areas are excluded.

The best start is a wild herb walk with a nature park, an adult education centre or a nature conservation group. There you see, smell and feel the features on the real plant, and a knowledgeable person corrects you. A good regional field guide with drawings of the features is then your most important tool. Apps and photos are at most an aid, never the sole decision.

Start small: three to five plants that you really know are worth more than fifty that you roughly know. Nettle, dandelion, plantain and hazelnut are good first species because they grow almost everywhere and are easy to tell apart. Note sites and features in a notebook – that way your knowledge grows from year to year.