Essential Autumn Perennials Collection

In autumn, the garden dons its final colours, and our collection of three perennials — Aster novae-angliae ‘Barrs Blue’, Sedum ‘Herbstfreude’ (or Autumn Joy), and Persicaria amplexicaulis ‘Blackfield’ — is designed to extend the flowering season in blue, pink, and burgundy. These are very hardy perennial plants (down to approximately –20 to –25 °C), with varied textures, whose flowering periods follow one another from late summer into autumn, from August to November.

The collection consists of 3 young plants:

• 1 x Aster novae-angliae ‘Barrs Blue’
  A remarkable New England aster with large, violet-blue daisies and a golden-yellow centre. Mature height: approximately 1.20 m, spread around 60 cm. Deciduous foliage resistant to diseases such as powdery mildew.

• 1 x Sedum ‘Herbstfreude’ (or ‘Autumn Joy’), Stonecrop
  Forms a medium to tall clump, with semi-evergreen foliage, blue-green in spring, turning yellow-orange in autumn. Flowers in wine-red short stems of bulb turning brown. At ripeness, it reaches 50 cm in height and 40-50 cm in spread.

• 1 x Persicaria amplexicaulis ‘Blackfield’, Ornamental Bistort
  It produces spikes of intense burgundy-red flowers, emerging from almost black buds. Mature height: 80-90 cm, spread around 50 cm. Lanceolate foliage, deciduous to semi-evergreen depending on climate, medium green turning red in autumn.

Plant this perennial collection in spring or autumn, outside of frost and extreme heat periods, to encourage good rooting. They will thrive in a sunny or lightly shaded border, in ordinary, well-drained, moist soil. Place the Sedum ‘Herbstfreude’, which is more compact, in the foreground of the border to form a robust base. Then position the Persicaria ‘Blackfield’, with its long red spikes, in the middle. Its generous flowering will structure the whole arrangement. Finally, place the Aster ‘Barrs Blue’, the tallest, in the background: its blue-violet clusters will form a brilliant backdrop.
Allow a spacing of approximately 50 to 60 cm between each plant, plan for 3 to 4 young plants per m², to give them room to flourish and create a natural scene.