To harvest the plant, simply pinch or cut the leaves off with a knife. Harvesting can be done throughout the growing season. Leaves are held erect on a sturdy stem, so they don’t get gritty, like spinach. When picking the leaves, remember the smallest leaves are the most concentrated in flavor.
Sorrel grows best in a rich soil, but will grow in any well-drained soil, and can be planted in sun or partial shade. Prepare the bed by digging in generous amounts of aged manure or compost. In the springtime, supply Sorrel with a feed and mulch. An occasional side dressing of compost is all that is required during the growing season. The plants should be kept moist, so water well during dry summer months. It is best to water Sorrel regularly as this prevents the Sorrel leaves from having a bitter taste.
When the plant is established, it’s easy to propagate by using a sharp knife to cut small sections from the main root. These sections should be planted 30 cm apart and watered in well. You can also start Sorrel from seeds. Sow seeds indoor in early spring, about a month before the last frost. Cover with light soil or sand and keep moist until it germinates, which will be about 9-10 days at 18-20 Celsius degrees (64-68 F). When the plants are about 5 cm high, thin the seedlings to 30 cm apart. Transplant them outdoors just after the last frost. The plants will grow into fairly sizable clumps and will produce tangy, edible leaves approximately four months after thinning. Remove the rust red flowers when they appear in summer by cutting the flowering stem, or the plant will put its energy into seed, not leaf, production. You can cut it all the way down, and it will grow back quickly.
Sorrel can also be grown in containers or indoors, in rich acidic soil that is moist. Sow in the fall for harvesting in the winter. It can be placed in full or partial sun, but if it gets very hot in your zone partial sun may be better. If you live in a mild climate, sorrel will stay green all winter, but will not grow as quickly. Due to their fecund nature it is best to grow Sorrel in containers to separate them from other members of the herb garden.