Yellow Loosestrife Growing, Planting, Facts & Care (Lysimachia vulgaris)
Lysimachia vulgaris is commonly known by several names, including yellow loosestrife, whorled loosestrife, garden loosestrife, and dotted loosestrife. This plant is a beautiful flowering perennial in the primrose family (Primulaceae). The Latin genus name of this plant is derived from Lysimachus, a Macedonian king and successor of Alexander the Great. Supposedly, this king used a plant from the Lysimachia genus to calm an agitated bull.
Yellow loosestrife is native to wetland areas in Europe and Asia but can also be found in North America, where it’s considered an invasive and very harmful plant in wetlands. This plant produces eye-catching yellow and orange blooms in clusters at the tops of its stems. These blooms can be strong attractants of a variety of pollinators.
Yellow loosestrife can be a problematic plant: although it can be a beautiful addition to some gardens, it is quite invasive outside of its native ranges. Another species, Lysimachia punctata is also called yellow loosestrife, but is considered to be somewhat less invasive. Lysimachia vulgaris can be distinguished from this other species by its affinity for wet soil, and by the way its blooms are clustered at the tops of its stems (terminal flowers) rather than spaced out along their lengths (axial flowers).
Facts, Benefits & Uses of Yellow Loosestrife
Yellow loosestrife produces beautiful yellow blossoms with orange centers that are attractive to pollinators. This species can be a beautiful addition to a wetland or pond garden in its native ranges in Europe and Asia. Yellow loosestrife was introduced to North America as an ornamental plant and has unfortunately gained a reputation there as an aggressive invasive species, as it overtakes native wetland vegetation and results in the degradation of these habitats.
This species is quite hardy, and can easily outcompete native vegetation, taking over important habitat. Interestingly, yellow loosestrife has even been found to outcompete other aggressive invasive species, such as purple loosestrife (Lythrum salicaria), also invasive in North America. Once established, yellow loosestrife is extremely difficult to remove. For these reasons, this plant is prohibited in various US states and should only be planted within its native range.
Yellow Loosestrife Growth, Hardiness & Climate
Yellow loosestrife grows quickly, reaching a maximum height of 18-36 inches within its first year. This plant re-seeds easily, and also spreads extremely well through underground rhizomes. In fact, yellow loosestrife spreads so well that it can easily outcompete other plants in the surrounding area.
This is an extremely hardy plant and grows easily without intervention. Yellow loosestrife does best in a wetland environment, and as such makes a great marginal pond plant. This plant is a perennial and can survive winters in USDA hardiness zones 4-8. Blooming typically occurs from June through September, and this plant’s yellow blooms are a beautiful ornamental addition to gardens. Yellow loosestrife flowers can also be great options as cut flowers indoors.
How to Plant Yellow Loosestrife In Ponds
Yellow loosestrife seeds are dependent on cold stratification in order to grow, meaning that they require a period of cold weather in order to emerge from dormancy. Gently press seeds just under the surface of the soil in autumn. There is no need to water the seeds yet, as they will not germinate until spring arrives. However, be sure to keep the soil moist once your seeds sprout.
If growing yellow loosestrife from an already established plant, simply bury the roots up to the crown of the stem in rich soil. This plant does best in moist, well-drained soils.
How to Care For Yellow Loosestrife
Yellow loosestrife does best when exposed to full to partial sun, although it can be tolerant of a certain degree of shade if necessary. You will get the most flowers out of your plant if it has the benefits of full sun and moist soil. Yellow loosestrife is extremely low maintenance and requires very little care so long as it is planted in a location with adequate access to water.
How to Winter Yellow Loosestrife
Yellow loosestrife is native to northern areas with cold winters, and as a result is able to survive cold weather without much difficulty. In fact, it is important that this plant is grown in areas with cold winters because its seeds rely on cold stratification to sprout in the spring. There is no need for any special treatment to prepare yellow loosestrife for winter when grown in its native hardiness zones. If growing outside of yellow loosestrife’s native hardiness zones, please consider whether this plant is invasive in your area.
Is Yellow Loosestrife Toxic, Poisonous or Invasive?
Yellow loosestrife is quite invasive in North America and is even prohibited in some locations. It can easily take over habitat from other plant species, and as a result can negatively impact fish, waterfowl, and aquatic invertebrate species as it results in a loss of habitat, shelter, and food for them. If you are set on growing yellow loosestrife in your pond or garden, be sure to plant it in pots and remove dead flower heads before they go to seed in order to prevent spreading.
The extent to which yellow loosestrife is toxic is not well known. Some gardeners report skin irritation when coming in contact with this plant, but this is not well understood. There are no reports of toxicity to people or animals currently, so it’s presumed safe to plant near ponds. For a short list of plants that are known to be toxic to fish, check out our guide here.
Is Yellow Loosestrife Edible? Will Fish Eat it?
The young leaves of yellow loosestrife are thought to be edible, at least in small quantities. However, this plant is not said to be very palatable. Anecdotally, yellow loosestrife has been used medicinally for gastrointestinal conditions and to clean wounds. There is no evidence that pond fish will try to eat yellow loosestrife. In fact, yellow loosestrife is known to displace fish habitat and limit their food options.
Where to Buy Yellow Loosestrife & Seeds? (UK & US)
Yellow loosestrife is easily obtained from plant nurseries in Europe and Asia, both in person and online. Elsewhere, you may have to order it online if you are set on having it in your garden. Keep in mind that if you are in North America, this plant may be prohibited in your area. As always, try to plant native species in your pond or garden whenever possible.