Aegopodium podagraria, commonly known as ground elder, is a herbaceous perennial native to Eurasia. Origin of its common name lies in the shape of its leaves and flowers, somewhat similar to elderberry. Ground elder is often cultivated as an ornamental plant. Due to its fast spread via rhizomes, it is considered an invasive species in certain countries.
I. Appearance and Characteristics
Aegopodium podagraria, commonly called ground elder, is a species of flowering plant in the carrot family Apiaceae that grows in shady places. The name “ground elder” comes from the superficial similarity of its leaves and flowers to those of elder (Sambucus), which is not closely related. Other common names include herb gerard, bishop’s weed, goutweed, gout wort, snow-in-the-mountain, English masterwort and wild masterwort. It is the type species of the genus Aegopodium. It is native to Europe and Asia, but has been introduced around the world as an ornamental plant, where it occasionally poses an ecological threat as an invasive exotic plant.
This herbaceous perennial grows to a height of 100 cm (39 in) from underground rhizomes. The stems are erect, hollow, and grooved. The upper leaves are ternate, broad and toothed. It flowers in spring and early summer. Numerous flowers are grouped together in an umbrella-shaped flowerhead known as a compound umbel. The main umbel is further divided into several secondary umbels known as umbellets or umbellules. Each umbellet has 15 to 20 rays (pedicels) that are each topped with a single, small, five-petaled white flower. They are visited by many types of pollinating insects.
The fruits, produced in late summer and autumn, are small and have long curved styles.
II. How to Grow and Care
Sunlight
Goutweed has a preference for partial shade conditions, but it can still do well in full shade and also full sun, providing it receives sufficient moisture. It will not flower as well under dense shade. Intense, direct sun can result in leaf scorch.
Temperature and Humidity
Goutweed can withstand very hot and very cold temperatures—its tolerance of extremes is one of the reasons it’s so hard to keep the plant in check. The seeds of goutweed do need cold winters in damp soil to germinate. The plant is not affected by high humidity.
Watering
In its native environments, goutweed is often found in damp forested areas, and it has a preference for moist conditions. It can even survive in saturated ground, and some gardeners will use it around pond areas. Water weekly if there is no rainfall. To avoid root rot, allow the top part of the soil to dry out before watering.
Soil
This plant isn’t fussy when it comes to soil types, providing it’s well-drained. It can also grow well in a wide range of pH levels, but it does seem to enjoy slightly acidic soils most.
Fertilizing
Given how hardy this plant is, it doesn’t need regular fertilization to thrive. In poor soils, however, some gardeners will add additional organic matter.
Pruning
Deadheading the flowers before they go to seed can help with spreading. However, it’s primarily the rhizomatous roots that make this plant so aggressive.
Many gardeners cut the flowering stalks back completely as they can look rather untidy if you’re using goutweed as a ground cover option.
Propagation
Dividing this plant or nurturing new growth from cuttings of the rhizomes is easy. It’s best to plant the divisions directly into the garden in the spring. Goutweed can be propagated through cutting rhizomes. Here’s how:
- Locate a rhizome, ideally in the spring, and dig underneath to lift it out of the ground.
- Using a clean, sharp knife, cut the rhizome into pieces with roots and shoots attached.
- Plant pieces directly in the ground or a planter bed at the same depth as the original plant.
- Water well until established.
How to Grow from Seed
Goutweed is easy to grow from seed. Again, it’s best to do this in the spring. Seeds need cold stratification and moist soil to germinate. The seeds will benefit from being sown in a cold frame before the germinated seedlings are planted out in the summer.
Overwintering
No specific care is needed. Goutweed is hardy enough to survive cold winters without additional protection.
Pests and Diseases
Common Pests & Plant Diseases
Known for being a hardy plant, goutweed is not badly impacted by either pests or diseases. If grown in a hot and humid region, however, the plant can suffer from leaf blight. Mowing the foliage back can be enough to rejuvenate it.
Common Problems
Goutweed doesn’t struggle with many pests or diseases, but it can be difficult to eradicate.
Invasive Growing
Mow or use a weed-whacker to get your goutweed as short as you can to help control it. To try to eradicate completely, dig deep, around 2 feet, and remove all roots and rhizomes. Avoid composting.
III. Uses and Benefits
- Ornamental uses
Ground elder is a spreading, ornamental plant used as ground cover in large outdoor landscapes. For the garden, this perennial can be useful near a border or controlled area, where it will be less likely to overtake other plants in the garden.
- Medicinal and Culinary uses
The tender leaves have been used since antiquity as a spring leaf vegetable, much as spinach is used. It is commonly used for soup. Young leaves are preferred as a pot herb. It is best picked from when it appears (as early as February in the UK and other parts of northern Europe) to just before it flowers (May to June). If it is picked after this point it tastes pungent and has a laxative effect. However it can be stopped from flowering by pinching out the flowers, ensuring the plant remains edible if used more sparingly as a pot herb.
It also had a history as a medicinal herb to treat gout and arthritis, applied in hot wraps externally upon boiling both leaves and roots together. Ingested, the leaves have a diuretic effect and act as a mild sedative. Its use as a medicinal herb has largely declined.
The plant is said to have been introduced into Great Britain by the Romans as a food plant and into Northern Europe as a medicinal herb by monks. It is still found growing in patches surrounding many monastic ruins in Europe, and descriptions of its use are found among monastic writings, such as in Physica by Hildegard von Bingen.
Do not confuse with extremely toxic poison hemlock and hemlock water-dropwort.
- Other uses
In Eurasia, it is used as a food plant by the larvae of some species of Lepidoptera, including dot moth, grey dagger and grey pug, although A. podagraria is not the exclusive host to any of these species.
IV. How to Control
Seed dispersal and seedling establishments are typically limited by shading, and new establishments from seed are restricted to disturbed areas. However Aegopodium podagraria readily spreads over large areas of ground by underground rhizomes. Once established, the plants are highly competitive, even in shaded environments, and can reduce the diversity of ground cover and prevent the establishment of tree and shrub seedlings.
Because of its limited seed dispersal ability, short-lived seed bank and seedling recruitment, the primary vector for dispersal to new areas is human plantings as an ornamental, medicinal or vegetable plant, as well as by accidentally spreading rhizomes by dumping of garden waste. It spreads rapidly under favorable growing conditions. Because of this it has been described as a nuisance species, and been labelled one of the “worst” garden weeds in perennial flower gardens.
Once established, goutweed is difficult to eradicate. The smallest piece of rhizome left in the ground will quickly form a sturdy new plant. All-green goutweed may be more persistent and spread more rapidly than ornamental, variegated goutweed varieties, making the all-green type particularly difficult to control. And all-green, wild type forms are known to reappear from seeds of variegated varieties.
Integrative management strategies that combine herbicide with landscape cloth, bark mulch, and hand weeding to control goutweed in a garden are largely unsuccessful because sprouting occurs from either rhizomes or root fragments left in the soil. Hand pulling, raking, and digging followed by monitoring to control goutweed may be effective; however, caution must be taken to remove the entire rhizome and root system. Removing flowers before seed set may help control the spread of goutweed. Because goutweed’s starch reserves are typically depleted by spring, removal of leaves in spring could be effective in starving the plant. Once goutweed has been removed, the patch should be carefully monitored periodically for a few years. New shoots should be dug up and destroyed. Revegetation with other plant materials is recommended.
Systemic herbicides such as glyphosate are recommended because A. podagraria will regrow if merely defoliated.
The most effective means of control is to prevent its establishment in natural communities. It is thus recommended to plant goutweed only on sites not adjacent to wildlands and in gardens where root spread can be restricted (e.g., between a sidewalk and a house). However, the aggressive nature of this plant makes even this strategy risky. Several states have banned sales of goutweed (also known as bishop’s weed).
