'Herbstsonne' AGM is a fabulous plant for the back of the border, growing up to 2m (6½ft) in height. It bears large golden yellow flowers with reflexed petals and a greenish-yellow central disc, and it makes an excellent cut flower.
'Herbstsonne' flowers from midsummer through to early autumn and looks particularly lovely with late summer-flowering perennials and ornamental grasses. It will thrive in a sheltered spot in moist but well-drained soil in full sun and tolerates partial shade. As with all tall herbaceous plants you will need to stake in spring.
Rudbeckia laciniata 'Herbstsonne' AGM is particularly suited to prairie-style planting and will also enhance a cottage garden theme. At Rosemoor we have planted it in sunny corners, sheltered by formally clipped hedges in the Hot Garden where it fits in happily with the planting of grasses and colourful mid-late summer flowering perennials. Here, we have combined it with bright yellow Solidago gigantea; Cornus alba 'Aurea' AGM with its yellow leaves forms an understorey. The front of this particular group has been given the ‘Chelsea chop’ to make it slightly shorter, it will also flower a little later. If the experiment works to the satisfaction of David Squire and his team, it will be cut down by a third each year in late May.
On the Long Borders, Lysimachia ciliata 'Firecracker' AGM makes a perfect partner with nodding star-shaped yellow flowers and contrasting deep purple leaves. Bright, yellow-flowered Euphorbia sikkimensis AGM is slightly shorter in stature than the rudbeckia linking it with the front of border plants. Elsewhere on the Long Border, it tolerates the shade of purple-leaved Prunus cerasifera 'Nigra' AGM, with the purplish bracts of Acanthus spinosus continuing the theme.
This versatile and stately plant makes a striking addition to the summer border, but if it is too tall for you, one of its many relatives is sure to find a suitable spot in your garden.
Rosemoor Plant Centre has a wide range of rudbeckias on sale, while stocks last, including 'Herbstsonne'.
This plant is also available online from the RHS Plant Shop