Ground elder

Ground elder is the most useful plant on this list precisely because it is the most hated. Picked young, the folded shoots taste of parsley crossed with celery leaf, cost nothing, and arrive in the exact weeks when nothing else is up. The one rule is that you have to catch them early — this is a four-week crop and it does not forgive lateness.

The four-week window, and what lateness tastes like

In the first fortnight the shoot is a tight, glossy fold with a pale stem, and it eats like the tenderest celery heart. By week three the leaflets have splayed and a soapy, slightly bitter note comes in behind the parsley. By week five the stems are hollow, stringy and genuinely unpleasant — and no amount of cooking rescues them.

The test is the fold. Pinch the top pair of leaflets: if they are still pressed together and the stem bends double without cracking, keep it. If the leaflets have separated and the stem snaps with a fibre edge, the plant has gone over and you are picking next year’s crop.

Because the whole crop is four weeks long, the sensible plan is to pick a large batch in week two — 2 kg or more — and process it all in one sitting: one third eaten fresh, one third frozen as purée, one third fermented. Picking a handful every day for six weeks gives you two good weeks and four bad ones.

The umbellifer problem, stated plainly

Ground elder belongs to Apiaceae, the family that also contains hemlock, hemlock water-dropwort and fool’s parsley — three of the most poisonous plants in Europe. This is the one identification on this site where a mistake is genuinely life-threatening, so the check has to be structural, not a smell test.

Ground elder tells itself apart by smell first: crush a leaf and you get a clear parsley-and-celery aroma with no musty or mousey note. Then check the stem is grooved and hollow between the nodes, the leaves are twice-compound with sharply toothed leaflets, and the plant is running as a continuous carpet on a rhizome rather than standing as a single upright stem from one base. Hemlock is one stem from one base, spotted purple at the lower nodes, with a hollow that is smooth and a smell of mouse. If the plant is flowering, the umbel is enough — ground elder flowers in flat-topped white umbels in June, well after the edible window, and you should not be eating it by then anyway.

Fermenting the surplus

Ground elder ferments unusually well because it is low in sugar and firm in the stem. Pack 500 g of cleaned shoots into a 1 L jar with 10 g of salt, 3 g of crushed juniper and a strip of lemon zest, then top with a 2 % brine until the solids sit 3 cm under. It will be visibly active on day three and ready at day seven.

The result is a sharp, herbaceous pickle that works as a side to pork or as the acid element in a potato salad. It keeps three months chilled. Do not try to ferment it for longer than ten days: the chlorophyll goes grey and the texture turns to wet string.