The “Hermes plant” refers to Good-King-Henry or Mercury Plant (Chenopodium bonus-henricus), a resilient and edible perennial vegetable. Cultivated for centuries, this ancient leafy green has largely faded from common knowledge. This article provides insights into its cultivation and utilization.
Understanding the Hermes Plant
Botanical Identity
The Hermes plant, also known as Good-King-Henry or Mercury Plant, is scientifically Blitum bonus-henricus, though formerly classified as Chenopodium bonus-henricus. It belongs to the Amaranthaceae family, which includes spinach, beets, and quinoa. This herbaceous perennial grows 18 to 36 inches (45-90 cm) tall, featuring arrow-shaped or triangular leaves often velvety underneath. Small, greenish-white flowers appear in clusters from May to July.
Historical Context and Common Names
The name “Mercury Plant” likely stems from historical medicinal uses. Good-King-Henry has been a cultivated edible green in Europe since the Middle Ages, particularly in Britain, Germany, and France. It was once a staple in cottage gardens and an important part of the Anglo-Saxon diet, sometimes referred to as “poor-man’s asparagus” due to its edible shoots. Its decline in popularity occurred with the rise of modern cultivated spinach varieties.
Cultivating Good-King-Henry
Site and Soil Preferences
Good-King-Henry is a hardy and adaptable plant, thriving in a range of conditions. It prefers full sun to partial shade, with partial shade often yielding the best harvest quality, especially in warmer regions. It tolerates sandy, loamy, and even heavier clay soils, but performs best in fertile, well-draining soil rich in organic matter. An ideal soil pH range is between 6.1 and 7.8.
Planting and Propagation
Good-King-Henry can be propagated from seed or by dividing established plants. For seed propagation, cold stratification for 8-10 weeks can significantly improve germination rates. Seeds can be sown directly outdoors in early spring or autumn, or started indoors 10-12 weeks before the last frost. Plant seeds about 1/4 inch deep, and once seedlings are established, thin them to 12-18 inches (30-45 cm) apart. Division of established clumps is best done in early spring.
Watering and Nutrition
Once established, Good-King-Henry requires minimal care. It is relatively drought-tolerant, but consistent moisture promotes better growth and yields. Water regularly, especially during prolonged dry spells, to keep the soil evenly moist. This plant is not a heavy feeder if grown in rich, organic soil. Amending the soil with aged compost or well-rotted manure before planting, and mulching annually, can provide sufficient nutrients and help retain soil moisture.
Pest and Disease Management
Good-King-Henry is generally robust and rarely troubled by significant pests or diseases, making it a low-maintenance crop. Slugs and snails can sometimes be a nuisance to young seedlings. Leaf miners might cause cosmetic damage to leaves, but rarely threaten the plant’s overall health. Powdery mildew can occur in humid conditions, but good air circulation helps prevent it.
Harvesting and Culinary Uses
Harvesting Good-King-Henry can begin once the plant is well-established, ideally allowing it to grow for a year before extensive picking. The young leaves are best harvested from early spring to mid-summer, offering a mild, spinach-like flavor. Older leaves can become slightly more bitter, but are still suitable for cooking. To encourage continuous new growth, harvest leaves a few at a time, cutting them 2 to 4 inches long from plants with at least 6-8 leaves. Young, unopened flowering shoots, sometimes called “poor-man’s asparagus,” can be picked from mid-spring to early summer and cooked like asparagus.
Good-King-Henry is a versatile edible with a flavor often described as mild spinach. It is rich in iron, vitamin C, calcium, and B vitamins. While young leaves can be eaten raw in small quantities in salads, they contain oxalic acid, which can be reduced by cooking.
The leaves are commonly boiled, steamed, or sautéed, serving as an excellent spinach substitute in various dishes like soups, stews, and stir-fries. The young shoots can be prepared similarly to asparagus, while the flower buds can be sautéed in butter. Seeds, resembling quinoa, can be soaked, rinsed, and ground into flour for baking.
Addressing Common Growing Issues
If Good-King-Henry experiences warm weather and long days, it may “bolt,” meaning it will quickly produce a flower stalk and go to seed. This can make the leaves tougher and more bitter. Providing partial shade during the hottest parts of summer can help mitigate bolting and maintain leaf quality. Yellowing leaves can indicate either overwatering, which can lead to root issues, or a nutrient deficiency, particularly if the soil is poor. Ensuring well-draining soil and enriching it with organic matter can prevent these problems. Although generally pest-resistant, occasional slug or snail damage to young plants can be managed with organic pest control methods like hand-picking or barriers.