With winter preparation now almost complete the Hot! border is looking rather empty. But at least there’s not much more work to do. This leaves the group with plenty of time to think about planting design. We’ll mostly be in the greenhouse but, weather permitting we’ll also be taking a look at a couple of beds designed by Laura Moreland in the walled garden and at an older design dating from the Heritage Lottery park improvement scheme around the ponds in the park. These will show us both the opportunity and the difficulty of designing with ornamental grasses.

Form, Texture and Colour

For this session we’re interested in those plants form, texture and colour and with what other plants might go alongside, in front or behind. Managing form and texture will have a big impact on the look of your border.

Form is is what is seen when first looking at a border from a distance. Every plant has a distinct habit, a unique shape and size which develops and changes as the plant matures. These shapes divide and define the spaces in the border. Some forms are more dramatic than others and so attract attention. The site of a specific plant may block a view, or open a sight-line, or alter the view. The form of the plants selected and their placement are critical to creating dynamic spaces and pleasing lines.

Thinking bout the Hot! border the first impression is of height and this is achieved with plants that have very distinctive forms. The bananas, bamboo, the giant reed and the castor oil plants all get to 2.5m+ but with completely different forms. None of these has been planted for their flowers – our interest is the impact of their form, texture and colour of the border as a whole. The rice paper paper plants and the fountain grass are also intended as structural components. Even the Canna ‘Purpurea’ are there more for its form than floral interest. These plants give structure and shape to the border They’ve been selected for their form, texture and overall colour.

Looking at the border as it is in August you can also see the value of repetition. The border uses repeated motifs – both species and shapes to give coherence to the border as a whole. Most obviously the two bananas on either side of the path to the shelter. These unify the two sides of the border and suggest that the two beds are both part of the same composition and should be regarded as a whole. There’s repetition too at the other ends of the beds with two large block of Cannas holding either end. The diagonal line tending toward the shelter on both sides is also a repeated motif using plants of all scales. The displacement of these diagonals help to give the border dynamism and a sense of movement.

Looking at a completely different style of border see how form and repetition are used by Piet Oudolf in his design for New York’s HighLine.

The Black eyed susan’s repeated every 15 metres or so draw the eye forward. In narrow sections of this 2km long elevated ex railway line park its important to keep the planting flowing forward. They rise above the massed Senecios and two grasses punctuating the border with their lax free-flowing form. Oudolf calls this ‘Matrix Planting’. Within the matrix Primary plants are grouped or planted in drifts.

In a wider section of the park the stooled Eucalyptus erupt from the mainly clumping species below again providing punctuation as the planting below subtly changes their form and colour providing dimension to the border and introducing the more wooded section beyond. A similar although lower effect can be obtained with perennials using emergent umbellifers like cow parsley or scattered taller perennials.

In Oudolf’s design world he is also planning for the forms of the plants when they’re dead. Here a matrix of dramatic seed heads climb out of the already browned grass flower heads. These grasses should continue to look good until February when they’ll be cut down to ground level only to shoot again in March.

In a more traditional herbaceous border you can also see the use of repetition. Here the sure hand of Gertrude Jekyll punctuates the border with dark red hollyhocks.

This example also illustrates the importance of texture. The holly hock have quite large leaves but these don’t predominate when planting amongst species with more filigrenous leaves. Managing texture is about managing the close view of the border. If you plant lots of coarse plants together you tend to foreshorten the view and the space will appear smaller. In a border with less than 2m depth it advisable to have sections of planting that allow the viewer to see ‘through’ the planting as this adds depth.

In the Hot! border you can see a very wide variety of textures and leaf shapes from the highly serrated Melianthus through the ‘elephants ears’ Taro to the 2m paddles of the red banana. The change of texture through the border coupled with the diagonal drifts creates movement and rhythm

Just a reminder of how the planning is done here’s a small section of the HighLine as a working drawing from Oudolf’s workshop

As an xmas excercise you are welcome to design a border to replace the perennial stock bed in front of the new decking. I’d like you to do this using only plants from this limited palette

Bistort Persicaria amplexicaulis Pink/Red
Yarrow Achillea filipendulina Yellow/Cream
Alium Alium spp. * Blue/Purple
Japanese Anenome Anenome x hybrida Pink/White
Flowering Sea Kale Crambe  cordifolia White
Michaelmas daisies Aster spp. Blue/Pink/White
Catmint Calamintha nepeta Blue
Cone Flower Echinacea purpurea Purple
Globe Thistle Echinops spp. Blue
Indian physic Gilenia trifoliata White
Helenium autumnale Orange/Red
Macedonian scabious knautia macedonica Crimson
Prairie Gay Feather liatris spicata Pink
Sea Lavender limonium latifolium Blue
Cardinal Flower Lobelia x speciosa  ‘Vedrariensis’ Blue
Maltese Cross Lychnis chalcedonica Scarlet
Milky Loosestrife Lysimachia ephemerum White
Bee Balm Monarda spp. Purple/Red
Turkish Sage Phlomis russeliana Blue
Salvia × superba/sylvestris
Sanguisorba spp.
Hoary Skullcap Scutellaria  incana Blue
Milk Parsley Selinum wallichianum White
Saw wort Serratula seoanei Purple/Pink
Betony Stachys officinalis Purple
Devils-bit Scabious Succisa pratensis Blue
Veronicastrum virginicum Blue/White
Gaura lindheimeri White
Toad Flax Linaria purpurea
Evening Primrose Oenothera biennis
Shade Plants
Masterwort Astrantia major involucrata
Actaea rubra
Japanese Anenome Anenome x hybrida Pink/White
Astilbe spp
Cimifuga japonica
Bishop’s Hat Epimedium pinnatum pale yellow
Hemp Agrimony Eupatorium purpureum Maculatum
Spurge Euphorbia polychroma
Cranesbill Geranium spp. white/blue/pink
Heleborus orientalis
Coral flower Heuchera micrantha white
Iris sibirica
Lathrus vernus Purple
Loosestrife Lythrum salicaria Pink red
Mertensia sibirica Blue
Phlox paniculata Blue
Soloman’s Seal Polygonatum odoratum White
Rosgersia spp
Burnet Sabguisorba spp
Ice Plant, Sedum Hylotelephium spectabile Pink/Red
Telima grandiflora rubra Red green white
Honesty Lunaria redivia
Lady’s Mantle Alchemila mollis yellow
Meadow rue Thalictrum aquilegiifolium pink
Spurge Euphorbia caracias
Foxglove Digitalis ferruginea
Dropteris spp
Shuttlecock fern Matteuccia struthiopteris
Shield fern Polysticheum setiferum