Winter hardy to USDA Zone 7 (Zone 6 with a protected location and winter mulch) where it is easily grown in moist, humus-rich, well-drained soils in full sun to part shade. Plants perform best in full sun in the northern parts of their growing range, but appreciate some part afternoon shade in hot summer areas. Plants will spread by creeping stems which root at the nodes to form an attractive ground cover, but are not considered to be invasive. Species plants may be propagated by division, cuttings or seed. Species plants will flower in the first year from seed and therefore may be grown as annuals.
Lysimachia congestiflora, commonly called dense-flowered loosestrife or golden globes, is a prostrate, mat-forming herbaceous perennial that grows to only 3-6” tall but spreads in the garden by creeping stems to 12” wide or more to form a dense medium green ground cover accented from late spring to mid-summer by showy cup-shaped bright yellow flowers. It is native to ditches, roadsides, edges of rice paddies, and damp forest margins in China, Bhjutan, India, Myanmar, Nepal, Sikkim, Thailand and Vietnam.
Stems are clad with opposite to whorled, ovate to broad-ovate medium green leaves (to 1 1/2” long). Leaves are semi-evergreen to evergreen in warm winter areas where temperatures do not drop below 15 degrees F. Some species plants with colorful variegated leaves have been found growing in the wild. Cup-shaped, 5-petaled, yellow flowers (to 3/4” wide) bloom in terminal clusters (3-8 flowered racemes) from late May to July.
Genus name honors of King Lysimachus of Thrace and is derived from Lysimacheios which was the ancient Greek name of a plant in this grouping.
Specific epithet comes from the Latin words congestus meaning congested and flos meaning flower in reference to the flower clusters.
No serious insect or disease problems. Lysimachia is susceptible to rust and leaf spots.
Good ground cover. Border fronts or rock gardens. Waterside gardens. Sprawl over rocky surfaces. Grow as an annual in hanging baskets or containers.