The Shrub Steppe Plantings at The Barbican

The ‘shrub steppe’ plant community continues the idea of the dry-adapted grasslands or meadow that form the basis of The Barbican plantings, but extends the concept to include a scattered and discontinuous shrub component together with small trees.  As such it is a multi-layered plant community with a strong structure that creates year-round visual interest.  Including shrubs and woody plants gives an extra dimension to the plantings, adds autumn leaf colour and additional flowering, but also importantly increases the wildlife value of the planting through creating additional bird habitat.

The inclusion of the shrubs and small trees was possible where the roof loading capacity enabled a greater depth of growing medium than was possible in the steppe areas alone.  It is important to note that this planting is not attempting to recreate any real shrub steppe planting communities that might be found in the wild.  Instead, it is more about the integration of an open shrub layer within the predominantly herbaceous perennial plantings.

The shrub steppe plantings in spring, soon after planting (with a lot of construction and site works still going on around).  Here, scattered Amelanchier lamarkii and Sambucus nigra ‘Gerda’ are planted amongst the perennial layer that, in its spring aspect, is visually very similar to the main steppe plantings, with the distinctive combination of Euphorbias and species Tulips.  However, some of the elements of the woodland planting (such as Brunnera macrophylla ‘Jack Frost’) are also incorporated close to the shrubs.

The ability to work with slightly greater depth of growing medium in the shrub steppe plantings allowed additional plants to be used that were not suitable for the thinner substrate depths of the pure steppe plantings.  The shrub steppe area is also slightly more sheltered, allowing the inclusion of some taller perennial species.  Here, in early summer, red Lychnis chalcedonica is prominent amongst Lychnis coronaria ‘Alba’ and Salvia nemorosa ‘Caradonna’, with the scattered shrubs of Amelanchier lamarkii.

The shrub steppe plantings in April and early May

In April and early May, the dominant visual impression is very similar to that of the main steppe plantings.  The main shrub at this time of year is Amelanchier lamarkii, which in addition to the spring blossom, has young leaves with a distinct coppery tint.

For more detail, and a gallery of images of the shrub steppe plantings in April and early May, click here

Steppe Plantings in late Spring and Early Summer

In late spring through to early summer there is a gradual transition from the vibrant jewel-box colours of earlier in the spring to a softer range of purples, blues and mauves.  The bright green bracts of Euphorbia characias fade away, and the foliage of the later-flowering perennials grows taller.  Many of these have blue-grey foliage, and combined with the grey-leaved grasses, the area has a soft greyish green tinge that is perfect for the blue and purple flowers.  Occasional deep red Oriental Poppies (Papavar bracteatum ‘Goliath’) stand out – the plants were small when established so in 2015 only a few of them flowered.  By early to mid June the first flowers of Allium ‘Purple Sensation’ are appearing.

For more detail and photographs of the shrub steppe plantings in late spring click here

The Shrub Steppe Plantings in Mid Summer

In mid-summer – late June to mid-July the shrubs steppe plantings reach a colour peak as the spring elements fade into the background, and the main flowering combinations of high summer materialise.  The pink flowers of the dark-leaved Elder, Sambucus nigra ‘Gerda’  make a striking combination with the scarlet of Lychnis chalcedonica, the crimson of Knautia macedonica and the blue of Scabiosa columbaria.  In fact the Lychnis is one of the main character species at this time, together with Salvia nemorosa ‘Caradonna’ and Achillea ‘Terracotta’.  Orange with white and a scattering of blue, red and purple characterise this time.

A key flowering shrub is Philadelphus ‘Belle Etoile’ – this low-growing Philadelphus is heavily scented and is planted around public seating areas.

For more details and photo gallery of the shrub steppe plantings in late June to mid-July, click here

Kniphofia ‘Tawney King’ begins its flowering period in mid summer

Philadelphus ‘Belle Etoile’ amongst the steppe perennials

For more detail and photographs of the shrub steppe plantings in mid summer click here

Philadelphus ‘Belle Etoile’ amongst the steppe perennials

For more detail and photographs of the shrub steppe plantings in mid summer click here

Shrub Steppe Plantings in Late Summer

In late summer (late July and August) there is yet another colour transition across the plantings as the late summer perennials take over.  The most dramatic plant is Kniphofia ‘Tawney King’ which starts out as strong orange and then fades to pale yellow.  This combines with Achilliea ‘Terracotta’ which by this time has similarly faded to pale yellow.  Strong colour is added through red Crocosmia ‘Emberglow’ and the intense blue of Echinops ‘Veitch’s Blue’.  Verbena bonariensis continues to flower.

To see more details and a gallery of photographs of the shrub steppe plantings in late summer click here

In September and October there is yet another transition across the whole site, as a different set of plants come to the fore.  The role and value of the shrubs and small trees becomes especially important.  These were selected in part for their autumn leaf colour display.  Amelanchier lamarkii becomes a beautiful orange, and Cornus kousa a dark crimson red.  The key character perennial is Anemone x hybrida ‘Honorine Jobert’ with clear white flowers.  This perennial establishes in the roof garden where the growing medium depth is slightly greater, but because this is a stressed site, it does not reach the height that it achieves in a more productive site.  The flowering of the Anemone is so profuse that in late summer and autumn white becomes the dominant colour in the shrub steppe plantings.  This is enhanced by this also being the main flowering period of Gaura lindheimeri ‘Whirling Butterflies’ which flowers diffusely amongst the grasses and seed heads of the earlier flowering plants.  Verbena bonariansis continues to flower.

The autumn colour of Amelanchier lamarkii, here with the very graceful and delicate flowers of Miscanthus ‘Undine’.

Below: Cornus kousa

Amelanchier lamarkii with Anemone x hybrida ‘Honorine Jobert’ and Verbena bonariensis.

Below Anemone x hybrida ‘Honorine Jobert’ and Gaura lindheimeri ‘Whirling Butterflies’

Anemone x hybrida ‘Honorine Jobert’ with Aster macrophyllus ‘Twilight’

For more detail and a gallery of photographs of the shrub steppe plantings in autumn, click here.