Ceratostigma plumbaginoides

The Ceratostigma plumbaginoides, also known as Creeping Plumbago, is an undershrub that can cover the soil through its trailing rhizomes. It blooms a vibrant gentian blue at the end of summer, complementing the bright red or raspberry colour of its foliage in September. This hardy, drought-resistant ground cover adds charm to the late season and can be placed in a rock garden, on a slope, along a path, or even in a pot on the terrace to beautify the base of a larger plant.

The Ceratostigma plumbaginoides (synonym Plumbago larpentae) is commonly called Leadwort or Lady Larpent's Plumbago. It belongs to the family of Plumbaginaceae, and is a cousin of Armeria and statices (Limonium). The plant is native to western China, where it grows naturally in rocky, dry and sunny areas. Often considered a perennial plant, it is a reddish trailing undershrub with fairly rapid growth, not exceeding 30 cm (11.8 in) in height, but capable of spreading over long distances if left unchecked. It can sometimes become invasive in moist and rich soil, but its development can easily be contained by removing overly vigorous rhizomes.

This plant has slender stems emerging from a woody base. The stems are quadrangular and often purplish. The leaves are ovate with pointed tips, measuring about 3-5 cm (1.2-2 in) in length and 2.5-3 cm (1-1.2 in) in width. The leaves are bright green in colour and have a border of dark, brownish to purplish cilia. In September, the leaves turn bronze and bright red before falling late in autumn. The colours are more pronounced when the plant is exposed to the sun.The flowering period is long, occurring from July-August to September-October depending on the climate. The plant has small clusters of 15 to 20 flowers with a diameter of 1.5 cm (0.6 in) at the terminal part of the stems and in the axils of the leaves. The flowers have 5 petals and form a unique combination with the foliage when it turns red. They are intensely coloured in gentian blue and enclosed in reddish-brown calyxes. Pollinating insects visit the nectar-rich flowers, which give way to bristly fruits that range in colour from brown to rust. The deciduous foliage appears late in spring, sometimes in May, and disappears with the first frost.

As a shrub that thrives in warm conditions and well-drained soil, even in sandy or gravelly soil, the Creeping Plumbago is an excellent addition to garden areas with poor soil and lack of depth. Over time, it forms a thick carpet that is particularly remarkable at the end of the season. It's also well-suited to cultivation in pots or containers, adding a beautiful splash of colour to the terrace, which may have fewer flowers during this time of year. In a rock garden or on a slope, it pairs well with the bright yellow flowers of Sternbergia lutea (the false autumn crocus). The beautiful glossy foliage of the latter will fill the ground in winter, and the two plants will combine their flowers in September. The Ceratostigma foliage remains decorative throughout the summer, hiding its companion's absence, which rests underground. Botanical narcissus, autumn crocuses, or botanical crocuses can also be planted in a carpet of creeping plumbago. It's an excellent plant for a dry garden with no watering.