PLANT OF THE MONTH: Panicum virgatum 'Shenandoah'
Panicum virgatum is a North American native, and 'Shenandoah' is a compact selection of this species. Its upright habit makes it perfect for the smaller garden, where it gives welcome autumn colour when other herbaceous perennials are beginning to fade.
In early summer, the leaf blades are tipped in red and by mid-autumn, the entire leaf is a rich burgundy. Late autumn sees the foliage fading to beige which remains upright into winter. This habit provides valuable cover for birds and small mammals.
This grass enjoys a sunny position and a moist well-drained soil; conditions readily available in the Hot Garden and in the Foliage Garden here at RHS Garden Rosemoor where it is planted in groups to give visual impact. We leave it until it starts to look untidy (usually well into the winter), when it is cut down to ground level ready for the new leaves to emerge in spring.
'Shenandoah' looks particularly effective with dark-leaved plants. We have placed it in combination with Phormium tenax 'All Black' in the Foliage Garden, where the red leaves and the weeping panicles of delicate red spikelets harmonise in colour but contrast in form.
In the Hot Garden it is used to contribute to the warm colours of autumn when the heat is beginning to die down and the more subdued colours of dusky reds, buffs and russets are beginning to take over.
If you want to grow grasses, then this is a good one to start with. It is relatively undemanding and combines well with a whole range of other herbaceous plants and shrubs. Its changing colour through the seasons gives it the edge over more static subjects and the delicate form of its panicles makes it a good "see-through" plant giving added depth to the border.