Lysimachia christinae Sunburst - Hillysun, creeping lysimachia

Lysimachia christinae ‘Sunburst’, also sold as Lysimachia ‘Hillyssun’ or Hillier™ Sunburst, is a carpeting perennial used as a groundcover in damp soil and as a trailing plant for planters, window boxes, and hanging baskets. This loosestrife is distinguished by its reddish stems, its dense, dark, and glossy foliage and its summer flowering in small yellow stars with a red heart. It is a very decorative plant on a windowsill, atop a low wall, or on the edge of a pond.

Botanically, Lysimachia christinae is a creeping herbaceous perennial from the Primulaceae family, like primroses. It is native to China and East Asia, where it is found in cool to damp places, on slopes, banks, meadows, and woodland edges, in regions with a humid subtropical climate. In these countries, the plant is also known as Jin Qian Cao, literally "gold coin herb", in reference to its small, rounded leaves and its ancient use in traditional medicine.
The cultivar ‘Hillyssun’ Sunburst is a recent horticultural selection developed for its very trailing habit, its good performance in pots and hanging baskets and its dark green foliage with well-defined red veins. It is marketed as a container plant to complement annuals with more voluminous flowers. The plant exhibits a creeping then trailing habit and rather rapid growth in moist soil. The stems are slender, cylindrical, smooth, and reddish. The plant spreads laterally and roots at the nodes that are in contact with damp soil. In the ground, it reaches a height of 5 to 10 cm with a spread of 1 m to 1.20 m; in a pot or hanging basket, the length of the trailing stems is particularly noticeable, often exceeding 60–80 cm in the space of a season. The rounded to slightly heart-shaped leaves resemble small coins. They measure 2.5 to 3 cm in diameter and have a fairly thick and smooth texture. The upper surface is a dark glossy green, while the underside is lighter. In ‘Sunburst’, the veins are marked with reddish-brown to purple. This foliage will be evergreen or semi-evergreen, depending on the severity of the winter. Flowering occurs from May to July – August. The solitary flowers are borne on short peduncles in the leaf axils. Each measures about 2 cm in diameter, forming a corolla composed of 5 spreading lobes with a narrower base, of a bright yellow, whose throat is tinged with orange-red around a small cluster of yellow stamens.
Ecologically and practically, Lysimachia christinae is suited to cool to damp soils, rich in organic matter, including pond edges or areas that are occasionally waterlogged. Its hardiness is around -15 to -18°C in well-drained soil. The plant tolerates occasional sun in a temperate climate if the soil remains moist, but prefers dappled sun or bright partial shade.

In the garden, this 'Sunburst' loosestrife creates a low carpet that quickly colonises damp borders and slopes, or the banks of water features; in containers, it forms very beautiful cascades. In a large rectangular planter, it can be combined with Heuchera ‘Caramel’ or ‘Obsidian’ for their volume and colourful foliage. In a planter on a partially shaded balcony, it will go with white or violet Petunia Surfinia® or small-flowered Calibrachoas like 'Noa Almond Blossom' (white) and 'Lia Dark Red' (red). On a terrace or stair rail, it can be planted in a deep hanging basket with a Begonia boliviensis ‘Santa Cruz’ or a Fuchsia ‘Mrs Popple’.