FOUNTAIN OF COLOUR
Lespedeza thunbergii is one of the best autumn-flowering shrubs and is a plant I have loved for many years. Its long stems and pea-like flowers that have a very similar look to wisteria, are perfect for trailing down a wall, and look wonderful when paired with the climbing perennial Lophospermum erubescens. Both prefer full sun, which should rule out this north-facing wall, but the temporary nature of this container display gives me more leeway.
How to achieve the look
At Sissinghurst we are lucky to have these wonderful old brick walls, which are remnants of an Elizabethan mansion that once stood on the site. Vita made sunken troughs by lining the excavated sills of the wall’s bricked-in windows with slate both on the bottom and the sides. In the bottom slates she drilled holes to aid drainage and sealed the joints to ensure not too much water or soil escaped.
In spring we generally fill these troughs with the biennial, pink wallflower, Erysimum cheiri ‘Giant Pink’, which flowers from late March to mid May from seed sown the previous June, and has proved very successful for several years now. Once the wallflowers are over we like to experiment with different plants. This year I am trying a combination of Lophospermum erubescens and Lespedeza thunbergii. Both are plants that don’t need too much deadheading so I won’t have to get the ladder out too often, Containers of trailing plants look great when they’re placed high on a wall, but you do need to think about maintenance. These troughs are not that high, but I do have to use a hose pipe fitted with a long watering lance to make the task easier. In October and November we lift the large, tuberous roots of the Lophospermum, as we would with dahlias, and keep them frost free through the winter before starting them into growth in early spring by potting them on into compost and watering. Only once the danger of frost has completely passed in late May do we plant them outdoors.
Plants
1 Lespedeza thunbergii Native to Japan, its long stems, which should be pruned to the ground each spring, have attractive foliage through summer and sprays of vivid purple-red, pea-like flowers from September. Useful for growing on banks, trailing over a wall or grown flat as a groundcover plant. 1.5m. AGM. RHS H5, USDA 4a-8b.
2 Lophospermum erubescens A tuberous plant from the mountainous areas of Mexico where it grows at an altitude of around 2,000m. Although classed as a tender perennial it is rapid in its growth so can be grown as an annual. 1.5m. RHS H2.