The leafy, spreading foliage normally doesn’t grow much taller than 10 inches, but the flowering stalks that appear in early summer can shoot up much taller. Its small, white flower umbels aren’t particularly ornamental, and some people simply cut the flowering stalks back to prevent the ground cover from looking untidy. It readily self seeds and its rhizomatous roots mean that it can be an aggressive spreader and difficult to eradicate once established. If you’re not careful, the leafy mounds could quickly take over your entire garden. Some regions classify it as an invasive species. If you do plan to plant goutweed, you might want to contain it to spots where other plants struggle to survive. There’s a variegated variety of the plant that is known for being less invasive, and this tends to be the most popular choice in gardens. The plant’s ability to grow in shady locations and a wide variety of soil types, make it a good option for cover under a group of trees. The spreading roots system can be helpful if you’re looking for plants to help tackle steep-sided soil erosion.
Light
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. Intense, direct sun can result in leaf scorch.
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.
Water
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.
Temperature and Humidity
Goutweed is a relatively cold-hardy plant and can survive winters that get as cold as five degrees Fahrenheit. It does best in temperate regions.
Fertilizer
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.
Propagating Goutweed
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.
How to Grow Goutweed From Seed
Goutweed is also easy to grow from seed. Again, it’s best to do this in the spring. The seeds will benefit from being sown in a cold frame before the germinated seedlings are planted out in the summer.
Common Pests and 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.
