Late summer border - colour verses structure?

It's shamefully been months since my last post, it's been a super busy year with one thing and another - going to try and write about some of the exciting projects I've been involved with over the next month or two. Thought I'd start with the most recent one - a garden I worked on which was opened under the Scotland Open Garden Scheme yesterday. A lady rang me in March asking if I could help her with plant design. I don't get asked for just planting plans very often so when I arrived I was delighted to find out she was looking for a late summer border, pure herbaceous - no structure, shrubs or year round interest required - even more rare. Coming down the stairs at the side of the house, I got first sight of the border that she wanted redone.

It's south facing, runs along the base of the wall of main terrace and is bookended by steps. The client had already started clearing it of plants, so it contained only some bulbs, Nepeta, Astanita & Peony. It was approx 14m long by around1.8m deep. Beyond wanting the planting to peak for the open day in late August, the client's brief was quite loose - no grasses, but she didn't mind what colours I chose. She asked for some Helenium, Verbena bonariensis and she was growing on some of her own Dahlia and Ricinus communis which she'd like to include if it fitted with the scheme (which it did!)

Standing half way down the lawn, looking back at the border I realised that the planting needed to be vibrant, with lots contrast in form and texture to be able to stand out against the handsome house just beyond it. So out came my favourite design & plant books, catalogues and the research began. I created a photo portfolio of plants, which the client & I looked at together on my laptop. She was very knowledgeable about plants, but I always find these really useful at this initial stage. They included the likes of: Achillea 'Gold Plate', Sedum 'Purple Emperor', Agastache 'Black Adder', Crocosmia 'Dusky Maiden', Echinacea 'Sunrise' and Kniphofia 'Nancy's Red'.

The client was pretty happy with everything on this master list, so then I then I set about refining it and thinking about planting combinations. One of my favourite books is 'Designing with Plants' by Piet Oudolf & Noel Kingsbury, and it was easy to adopt a lot of the principles they describe in here - mainly that 'Structure is the most important component in a successful planting: colour is important too but it is a secondary consideration. If the forms and shapes of plants in a border work well together...it is difficult to imagine an unharmonious colour combination arising'. So, here's the plan I came up with. I colour coded all of my plans and have included photos. 

I thought it might be interesting to look at some of the combinations in more detail & the process I use to create them. In the book I mention above, the authors discuss the relationship between colour & form, with 4 main principles:

1) Related shapes and related colours - that the subtle interplay between 2 or more very similar shapes and colours can create a powerful impression. An example of this here is Coreopsis 'Sunray', Helenium 'Wyndley' and Rudbeckia 'Goldstrum' at one end of the border.

An even simpler combination is the use of the tall Achillea 'Gold plate' and the shorter Achillea 'Moonshine' - far enough apart to not jar, but close enough to make the association between the two whilst looking down the border.

2) Different shapes + related colours - the white border and the colour themed borders at Hadspen House are testament to these being successful, but I tend to steer away from overusing this. However, here the purple of Agastache 'Black Adder', Verbena bonariensis and Thalictrum 'Hewitt's Double' look beautiful and glow in the late afternoon sunshine.

3) Related shapes + different colours - this is one I use a lot, think it can be very successful. As Piet and Noel warn though 'how much contrast is considered harmonious is a matter of personal taste'. A really simple example here is the yellow Achillea 'Moonshine' and then further down the border the gorgeous coppery orange Achillea 'Walter Funcke'.

One of my favourite ways of doing this is via daisies, there are a particularly large choice for late summer borders. I've included Echinacea 'Sunrise', Helenium 'Moerheim Beauty', Echinacea purpurea 'Magnus', Rudbeckia 'Goldstrum' and Helenium 'Wyndley'.

4) Different shapes + different colours - this can be tricky if the whole border is filled with this, but if the scheme contains enough of the above three principles then I throw some of these in.What's not to like about Agastache 'Black Adder' next to Echinacea 'Sunrise'??

Or Salvia 'Caradonna', Monarda 'Ruby Glow' and Helenium 'Wyndley'...??

This was an incredibly fun project to work on and the open day was a great success raising almost £3000 for charity. I learned loads and it just emphasised that if I follow the principles outlined above then I can't go far wrong. But let me know what you think...