The sorrel plant is a leafy green herb that produces tart, lemony leaves. It’s part of the Polygonaceae family, and is a low-maintenance plant that’s packed with flavor. This versatile green can be used fresh in salads and sandwiches, or as an ingredient in soups, savory pies, and more. It can be grown in a raised bed or garden, or as part of an indoor herb garden.
Just be warned: like spinach and rhubarb, sorrel leaves contain oxalic acid, which is toxic in large amounts. That said, it’s fine in small quantities unless you’re extremely sensitive to it. If a significant amount of sorrel is consumed, is can also be poisonous to animals.
As a result, animal-loving gardeners may want to either avoid this plant, or grow it in a raised area away from inquisitive pets.
Unlike other herbs, there aren’t many named varieties of sorrel. Your choice will largely be between garden sorrel (Rumex acestosa) and French sorrel (Rumex scutatus). There are, however, some other options to choose from.
Garden sorrel or sheep sorrel is native to North America. It can grow up to 3ft in height and produces distinctive, long, leathery leaves. Garden sorrel leaves taste best when they’re young and tender. Try them in traditional sorrel soup, or raw in spring salads.
Also known as buckler-leaved sorrel, this variety does well in poor soil. It produces small, shield-shaped green leaves that have a subtle citrus flavor. It’s a small plant, and commonly used as a culinary herb throughout Europe. A fully grown French sorrel plant is about 6in high and 8in wide.
This is a common garden herb with smooth or crinkled leaves. The upright stems of this variety can reach 2ft in height, and if it’s allowed to bolt it’ll produce attractive purple flowers.
Red veins mark this variety’s bright green leaves. It can grow to 3ft in height, and red-veined sorrel is less tart than French sorrel. As a result, it’s great in salads, even when a bit more mature.
Growing your own Sorrel Plant from seed
You can begin to sow sorrel seeds outside 2-3 weeks before the last frost date and continue until late July.
Sow the seeds in a tray filled with fresh potting or general purpose compost, and water gently with a fine spray. Place the trays in a bright position and allow them to germinate. These seeds are light-dependent, meaning they need direct sunlight in order to sprout. Don’t cover them with any soil.
Once the seedlings are large enough to handle, divide the root ball. Plant the healthiest seedlings into their own 2-inch pots. Keep transplanting into larger pots as the sorrel plants continue to grow. Eventually, they’ll grow large enough to sit comfortably in an 8- to 12-inch pot.
If you’re sowing seeds straight into the ground or a raised bed, sow the seeds half an inch deep, spacing 2-3 inches apart. Following germination, when the plants are 6-8 weeks old, thin out the seedlings to a spacing of 12-18 inches. Space each row 18-24 inches apart.
Planting Sorrel Outside
Sorrel is a hardy plant, so in USDA zones 4 and warmer it can be grown as part of a perennial vegetable garden. It’ll keep growing back year after year, and will spread (and self-sow) enthusiastically. Grow sorrel as an annual in cooler zones. These plants do best in full sun, but like a number of other herbs, they’ll also grow in shadier spots.
This herb prefers to grow in a well-draining soil that’s rich in organic matter, and slightly acidic. With with a pH between 5.5-6.8 is ideal. Harden off young plants after the last frost has passed. During this period, you can prepare the soil by digging it over and working in some organic matter. This will encourage healthier growth.
To plant the sorrel, dig a hole that’s slightly larger than the root ball. The lowest leaves of the sorrel plant should sit just above the soil when placed in the hole. When you’re happy with the plant’s position, fill in the hole and water well. Mulching around the plant will help to preserve moisture and discourage weed growth.
If you’re planting more than one sorrel plant, make sure that they have enough room to grow. Space sorrel plants to a distance of 12-18 inches.
Caring for Sorrel Plants
Sorrel is a quick-growing, low maintenance plant. This is largely because it has a deep, persistent tap root. However with the proper care the plant will be healthier and will produce more, better tasting leaves.
Sorrel plants like to be evenly moist. Water your plants regularly, don’t let them dry out.
Sorrel doesn’t need fertilizing, especially if it is planted in rich, fertile soil. However an application of general purpose, granular fertilizer in the middle of the growing season will give the plant an extra boost.
Pruning and Dividing
Prune away any old or disfigured leaves.
Divide perennial sorrel plants every 3-4 years. This helps to keep the plant healthy and encourages fresh growth. Older plants can become tough and lose some of their flavor, so dividing the plant helps to prevent this. The best time to divide sorrel is in the spring, before fresh growth emerges, or in the fall. If you don’t want to divide your plants, grow them as annuals, starting again with fresh seeds each spring.
Sorrel plants bolt when the warmer weather comes in June or July. This means that they start to produce a flower spike. Pinching off the flowering spikes prevents the plant from producing seeds, and also increases and prolongs productivity.
Alternatively, if you are growing sorrel as a perennial, allow the flower to bloom. By early August the plant will have flowered and seeded. Fresh sorrel leaves will then start to emerge at the base of the plant. If the plant is allowed to flower, remember to remove the seed head. This will prevent the plant from self-seeding and spreading throughout the garden.
Common Sorrel Plant Problems
Sorrel is a largely problem-free plant.
Try not to over-water it during damp periods to avoid rot. Also, remember to reduce watering in the fall and winter. While the root of the sorrel plant is quite durable, an extended period sitting in overly wet soil can lead to disease or infection. If you’re growing sorrel in pots, raising the pots off the ground and onto bricks will encourage better drainage.
Most pests tend to leave sorrel plants alone—the most common irritant is aphids. Should these settle on your plants wash, them away with a hosepipe. Regularly thinning the plants will make them less attractive to aphids.
Sorrel is a hardy plant that does well with a number of other crops. This makes it a useful companion plant. Many people choose to grow it as part of a vegetable or herb garden, as the plant does particularly well with thyme, sage and rosemary. Sorrel also does well with low-growing crops such as strawberries.
Avoid planting sorrel with tall plants such as beans, peas, or corn. These will block out significant amounts of light, stunting the growth of the sorrel plant.
If you can’t wait for sorrel to fully mature—about 2 months after germination—you can begin harvesting young sorrel leaves when they’re about 4 inches long. If harvested regularly, as a cut-and-come-again crop, the plant will produce a regular supply of tender leaves. Young sorrel leaves are delicious, and also have more flavor than older leaves.
To harvest the sorrel, simply use clean scissors or secateurs and cut away some leaves. Harvest only what you need, as sorrel wilts quickly and doesn’t keep well.
These leaves taste best fresh, in salads or sandwiches. You can also cook them, either as a substitute for spinach or by dissolving them into a variety of dishes.
While sorrel will keep in the refrigerator for a couple of weeks, their flavor and texture won’t last. You can freeze leaves if you want to keep them for longer, but the flavor will fade quickly. Drying is also an option, though the flavor will be very subtle.
Harvesting Sorrel Seeds
To harvest sorrel seeds, you’ll need to allow the plant to flower and go to seed.
Carefully harvest the seed heads by covering them with paper bags, and cutting them off the stems. Tie the bags tightly around the stems and hang upside-down in a warm, dry spot for six weeks. Then shake the bag enthusiastically. Once opened, you’ll find a cluster of sorrel seeds at the bottom.
Store these seeds in a marked, paper envelope to use the following year.