If the Christchurch Botanic Gardens is the city’s crowning glory, then its herbaceous border is the jewel in the crown, and its curator for the past 15 years, David Barwick, the Peter Fabergé of the Pacific.
Mary Lovell-Smith focuses on the Botanic Gardens’ herbaceous border.
The border, an impressive 165m by 6m, has been lauded as the finest in the southern hemisphere often during its 92 years.
When it was laid out in 1926, it replaced a mixed border of trees and shrubs with ribbons of perennials and other flowers running through. Conceivably, it aroused a certain curiosity among the citizens as it would have been novel. As David explains, although herbaceous borders date to the late 1800s in England, Europe and the US, “New Zealand was a bit behind the times.”
He says that the rise of the border and its subsequent popularity throughout Western gardens was helped by cheap labour (the borders are labour intensive) and the ready availability of plants. Since the 1700s, plants had been flooding into Europe from around the globe; by the 1800s, “they were coming out of the grand estates and into mass production”.
A herbaceous border is, by definition, a border filled with herbaceous plants, predominantly perennials, usually aided and abetted by some bulbs and grasses. Beyond that, there are no hard and fast rules – apart, that is, from creating a magnificent display!
The Botanic Gardens border changes along its length in response to the varying soil and amounts of sun.
The east end is protected from cool easterlies by the old Robert McDougall Art Gallery and the Christ’s College building. Mature trees fend off the cold southerlies. “It’s a suntrap and can get very hot in summer in the afternoons,” says David. Here, the soil is light, often sandy and free-draining.
The predominant plants have vibrant hot-coloured flowers and are mainly from Mexico, South America and South Africa. These include red-hot pokers, crocosmias, salvias, geums and cannas. Some pale colours appear, the likes of artemisias, whose soft silvery foliage are used to break up the hot hues. Overhanging trees in the adjacent shrubbery create pools of shade, so David uses a red-leaved lysimachia and Euphorbia ‘Fireglow’, which like damp shade yet still fit in with the hot colour scheme.
David talks about crafting the colours, of “incrementally modifying the border every year, chipping away at it”, of seeing a colour scheme that doesn’t quite work and changing it.
Other changes are for pragmatic reasons.
The tall, brightly coloured cannas used to sit at the back of the border but David has had to move them to the front after legions of tourists would trample over plants to be photographed with them. David blames this relatively recent phenomena on cellphones and digital cameras.
Halfway down the border is the sundial. Beyond it, the soil is heavier – a silty loam. Overall temperatures are lower, it gets frosts and Douglas firs shade it in winter. Consequently, it more resembles a traditional English border.
“West of the sundial starts off with prairie flowers, such as phloxes, crambes, euphorbias, Tradescantia virginiana,” David says. “These generally have softer colours – blues, purples, mauves, cream, softer yellows, but also some hot colours.”
At the western end of the border, woodland plants do best – the likes of thalictrum, Solomon’s seal, rodgersia, astilbes and hostas. “There will be asters in sunny patches sprinkled along the border. If things sulk or get too hot they are moved. There are no hard and fast rules… because of the nature of herbaceous borders, plants are always on the move.”
It is not just about flower colour or plant size either.
Leaf shape, shade and texture must also be considered in the overall look.
David maintains the border mainly alone but has help from volunteers and staff at busy times, such as in autumn and early winter when plants are divided and replanted, and in early spring when the first flush of weeds come through. The quietest time is the dead of winter, “when you wouldn’t want to split and replant as they would rot.” Summer, too, is quiet. “The weeds are under control… though you may get the odd sow thistle.”
Density of planting helps control weeds but too much intermingling of different species is generally frowned upon in border maintenance. More vigorous varieties may get “a spade around the edges” to stop them spreading.
The entire bed has a layer of commercial compost spread over it in winter (the Gardens no longer makes its own) – all that is added in the way of feed. David says too much fertiliser means the plants grow too fast, become floppy and need staking. Likewise, singles predominate as doubles tend to need staking.
Border fans will say anytime is good to visit it. David may agree but says it really looks its best in January and February. He loves it, too, in spring, when new shoots are poking through the soil, and the leaves unfurl in fresh perfection. It’s not such a good look in winter though. “We don’t have the hoar frost to create that wonderful winter wonderland effect, but I do leave some seedheads for the birds.”
Christchurch Botanic Gardens’ herbaceous border.
Plantings are dictated by soil and sun.