Sorrel

Sorrel is a plant worth growing for its timing alone. While the rest of the garden is still bare or barely showing green, sorrel is already up and producing harvestable leaves — often weeks before the last frost date. It overwinters as a root crown and sends up new growth as soon as soil temperatures rise above 40°F. In most of the country, that means sorrel is the first green thing you pick in spring. The flavor is why you plant it: tart, lemony, and bright, caused by oxalic acid in the leaves — the same compound that gives rhubarb its pucker.

Direct sow seeds about 3 weeks before your last frost — sorrel seeds handle cold soil well and germinate at temperatures as low as 45°F. Press them into the surface shallowly; they need light to germinate. Thin seedlings to 18 inches once they're established. You can also start them indoors and transplant early, though direct sowing is straightforward. From seed, expect usable leaves in about 60 days. In subsequent years, the plant returns from the roots without any replanting needed.

The main management task with sorrel is cutting the flower stalks as they appear. Sorrel sends up tall seed stalks in midsummer — a signal that the plant is shifting energy from leaf production to reproduction. Once the flower stalks form, the leaves become smaller, tougher, and more intensely acidic. Cut the stalks to the ground as soon as they appear. The plant will reset and produce another flush of tender leaves. Without this, a sorrel plant left to bolt will decline significantly as a food plant.

French sorrel (Rumex scutatus) is a distinct species worth noting. The leaves are smaller and more rounded than common sorrel, the flavor is milder and less sharply acidic, and the plant tends to stay lower and more compact. Many cooks prefer it because the flavor is more nuanced — similar to lemon but without the bite becoming overwhelming when large quantities are used. It's worth growing both if you have room: common sorrel for big flavor, French for subtlety. Red-Veined sorrel (Rumex sanguineus) has striking crimson leaf veins and a milder flavor than either; it's primarily ornamental but edible.

Sorrel leaves contain oxalic acid, and eating large amounts regularly is not advisable for people with kidney stones, gout, or rheumatoid arthritis. Normal culinary use — a handful of leaves in a soup, a few leaves torn into a salad — is fine for most people. The oxalic acid breaks down considerably with cooking. Sorrel soup is a traditional preparation: the leaves cook down into a silky, muted-green puree in minutes. In raw preparations, the flavor is at its sharpest. The leaves hold in the refrigerator for about three days before wilting.