Botanists’ gardens: Maarten Christenhusz

Join me for a tour of the private London garden of botanist Maarten Christenhusz

Botanists gardens

What is it about some gardens that makes them particularly special and memorable? A sophisticated or original colour combination? A masterly display of contrasting shapes and textures? A clever design, leading you on a journey which hints at unexplored delights hidden around the next corner? Or perhaps a garden which conjures up feelings of tranquillity and wellbeing? For me, all these elements are important. But what really gets my pulse racing are the plants: gardens crammed full of rare, unusual, spectacular or unexpected plants, thriving under the care of a skilled gardener.

My own passion for plants developed while working as a botanical curator at Kew Gardens and the Natural History Museum. Unlike those with an interest in marine mammals, say, or birds or butterflies, botanists have the advantage that they can keep the objects of their interest alive at home, for study and for the pleasure and challenge of growing them and arranging them into a pleasing display.

Botanists know that with around 400,000 species of vascular plants in the world there are much more interesting plants to try growing than the usual suspects for sale at the local garden centre.

Maarten Christenhusz garden from above.
From above, Maarten’s garden appears as a lush and densely-planted oasis, in stark contrast to the garden next door. The Catalpa ovata tree is visible in the bottom left, with the Tapiscia sinensis beyond.

So what do botanists’ gardens look like? I’ve known a number of botanists over the years, and some have no interest in growing plants. They are happiest when plants are dead, pressed and filed in a herbarium where the world’s flora can be studied without the need to venture outside. Others use their gardens as a laboratory, filling them with countless specimens of very similar species of whatever group they are expert in, without necessarily a view to aesthetic considerations.

But for many botanists, a passion for studying plants and creating beautiful gardens go hand in hand, and so I decided to visit the private gardens of some gardener-botanists in the hope that they would turn out to be special and memorable gardens that I would enjoy visiting. My first such visit did not disappoint.

Maarten Christenhusz with Musa basjoo
The front garden has a milder microclimate and the planting includes a flowering Musa basjoo and a Dicksonia antarctica tree fern.

Maarten Christenhusz, Mike Fay and Mark Chase

My first trip took me to Kingston-upon-Thames, just down the road from Kew Gardens in southwest London, to meet freelance botanist Maarten Christenhusz in the private garden that he shares with fellow botanists (both senior researchers at the Royal Botanic Gardens, Kew) Mike Fay and Mark Chase. The three have recently co-authored the lavishly illustrated book Plants of the World, an essential reference for botanists, horticulturalists and plant lovers. I already knew that a number of the photographs for the book were taken in their garden, so I was excited to see it and had high hopes that I would encounter some interesting species. But can a plant-lover’s garden also be a beautiful garden?

Their garden proves that a collection of interesting plants can also be artfully arranged and beautiful to look at.

Colourful flowers in the garden of Maarten Christenhusz, clockwise from top left: Penstemon campanulatus (Plantaginaceae), Tulipa 'Royal Standard' (Liliaceae), Pontederia cordata (Pontederiaceae) and Nymphaea sp. (Nymphaeaceae) in pond, Kniphofia rooperi (Asphodelaceae), Prostanthera cuneata (Lamiaceae) and Hibbertia hirsuta (Dilleniaceae).
Colourful flowers in the garden, clockwise from top left: Penstemon campanulatus (Plantaginaceae), Tulipa ‘Royal Standard’ (Liliaceae), Pontederia cordata (Pontederiaceae) and Nymphaea sp. (Nymphaeaceae) in pond, Kniphofia rooperi (Asphodelaceae), Prostanthera cuneata (Lamiaceae) and Hibbertia hirsuta (Dilleniaceae). Photographs all by M. Christenhusz.

The garden is entered from a raised terrace (full of plants of course), from where my first impression was was how colourful it was. Maarten explained that he loves colour, which he tries to maintain throughout the year by mixing the botanical curiosities with many herbaceous perennials, roses and unashamedly vibrant bedding plants such as begonias and petunias. He comes from the Netherlands, so it was no surprise to hear that Maarten also loves tulips, which put on a spectacular display in the spring (in particular triumph tulips which he finds are reliably perennial even in his clay soil).

The three botanists have all published extensively on orchids (Mike Fay is chairman of the IUCN Orchid Specialist Group), so it was also no surprise to find a beautiful Vanda orchid in full flower on the terrace, as well as numerous hardy orchids planted around the garden.

Vanda orchid and the hardy orchid Cypripedium 'Lady Dorine' in Maarten Christenhusz garden.
Vanda orchid (left) and the hardy orchid Cypripedium ‘Lady Dorine’ (right, photograph by M. Christenhusz).

On one side of the entrance to the garden is a fine specimen of Sophora ‘Sun King’ (a member the pea family, Fabaceae) an evergreen shrub which, despite its exotic appearance, is hardy through most of the UK.  Attached to the Sophora is an air plant Tillandsia duratii (Bromeliaceae), which adds to the exotic effect (the Tillandsia is not hardy and is brought into the conservatory over winter). On the other side of the entrance is Eucryphia × nymansensis ‘Nymansay’ (Cunoniaceae), a vigorous shrub or small tee with an upright, columnar habit (handy for small gardens) which is smothered in large white flowers with numerous stamens in late summer and autumn.

Sophora 'Sun King' (Fabaceae) in Maarten Christenhusz garden.
Sophora ‘Sun King’ (Fabaceae). Inset: flowers (photograph by M. Christenhusz).

Beyond the terrace, other than a path leading to the bottom of the garden, the garden is given over entirely to plants, with a generously-sized pond providing a pleasing focal point, as well as home to many aquatic plants, including Penthorum sedoides and Anemopsis californica.

The pond in Maarten Christenhusz garden.
The pond.

The boundaries of the garden are hidden by shrubs and climbers and height is provided by two trees. The first is a fine specimen of Catalpa ovata (Bignoniaceae), a small tree originating from China with a spreading canopy which bears showy white flowers in summer, followed by long, thin seed pods. Maarten grew it from seed in 2006 but it blew over in a storm not long after he planted it out in the garden. Remarkably though, a side shoot grew up to almost match the tree’s original height in just a single season, and now it forms such an elegantly shaped small tree you would never guess its troubled past.

Flowering shrubs in Maarten Christenhusz garden, left to right: Eucryphia × nymansensis 'Nymansay' (Cunoniaceae), Azara serrata (Salicaceae) and Drimys winteri (Winteraceae).
Flowering shrubs, left to right: Eucryphia × nymansensis ‘Nymansay’ (Cunoniaceae), Azara serrata (Salicaceae) and Drimys winteri (Winteraceae). Photographs by M. Christenhusz.

The other tree is also one of the rarest plants in the garden: Tapiscia sinensis (Tapisciaceae). Also a small, deciduous tree from China, it has pinnate leaves and bears panicles of white, honey-scented flowers. It was introduced to horticulture in 1908 by Ernest Wilson, who collected it for the Arnold Arboretum in Boston, USA, but the species remains very rarely grown in the UK.

Tapiscia sinensis (Tapisciaceae) in Maarten Christenhusz provides dappled shade for a seating area at the bottom of the garden.
Tapiscia sinensis (Tapisciaceae) provides dappled shade for a seating area at the bottom of the garden.

Two climbers which caught my eye were Aristolochia sempervirens (Aristolochiaceae), an evergreen woody climber from southern Europe with glossy leaves and unusual curved, tubular flowers (hardy through most of the UK) and Bauhinia yunnanensis, with its distinctive camel’s foot-shaped leaves. Bauhinia is a genus of more than 500 species of tropical trees, shrubs and climbers known as orchid trees due to their showy flowers. B. yunnanensis is exciting as it is perhaps the only species which can tolerate frost, and has proved hardy in London gardens. My own seed-grown plants have survived outdoors for several years, but have yet to flower.

Aristolochia sempervirens in Maarten Christenhusz garden.
Aristolochia sempervirens.
Bauhinia yunnanensis (Fabaceae) in Maarten Christenhusz garden.
Bauhinia yunnanensis (Fabaceae). Inset: flowers (photograph by M. Christenhusz).

Like all gardeners, Maarten has a particular soft spot for certain groups of plants, and in his case this includes members of the plant families Araceae and Winteraceae (of which he grows 5 species, including a beautiful specimen of Drimys winteri).

Arisaema amurense (left) and A. sikokiana (right), in Maarten Christenhusz garden, both in the Araceae family.
Arisaema amurense (left) and A. sikokiana (right), both in the Araceae family. Photographs by M.Christenhusz.

The garden path leads to a small rockery, with a fine clump of the borderline-hardy pineapple-relative Ochagavia carnea (Bromeliaceae) from Chile and several Proboscidea louisianica (Martyniaceae). This annual herb from the southwestern United States and Mexico has beautiful flowers and is known as the devil’s claw plant due to the unusual fruit which has a bizarre alien-like appearance when dried. The plant is thought to be protocarnivorous: it produces short, glandular hairs over most of its surface, coated in a sticky resin which traps insects. It does not have digestive enzymes to absorb nutrients directly from insects as true carnivorous plants do, but instead relies on the natural breakdown of the insects by microbial activity to provide additional nutrients. Maarten kindly gave me some seeds, and I’ll definitely be growing it next year.

Unusual plants in Maarten Christenhusz garden. From left to right: Phyllocladus trichomanoides var. alpinus, Cestrum sp. and Ochagavia carnea.
From left to right: Phyllocladus trichomanoides var. alpinus, Cestrum sp. and Ochagavia carnea.
Proboscidea louisianica (Martyniaceae) in Maarten Christenhusz garden.
Proboscidea louisianica (Martyniaceae).

At the bottom of the garden is a secluded seating area, enclosed by a Cordyline, a thicket of Musa sikkimensis bananas (Musaceae) and a large Cestrum shrub (Solanaceae) covered in golden yellow flowers (possibly Cestrum  auranticum?). An arrangement of pots brings together a variety of plants with nicely contrasting shapes, colours and textures. I particularly liked Phyllocladus trichomanoides var. alpinus a species of conifer in the Podocarpoceae family from New Zealand, commonly called alpine celery pine. It is a very slow-growing, hardy evergreen shrub with attractive glaucous grey “leaves” (actually modified shoots called phylloclades), definitely one for my own wish list.

A view of Maarten Christenhusz garden.

At the far end, a lean-to greenhouse against the bottom wall of the garden provides space for propagation, and for growing tender plants. Here I found palm-like Lobelia gibberoa (Campanulaceae) from West Africa and a good-sized Doryanthes palmeri (Doryanthaceae) from Australia. Also known as the giant spear lily, the huge spike of red flowers can reach several metres long. It takes 10-12 years to flower though, so Maarten has a few more years yet to wait for the spectacle.

Tender plants in Maarten Christenhusz garden. Left: Doryanthes palmeri (Doryanthaceae), right: Lobelia gibberoa (Campanulaceae).
Left: Doryanthes palmeri (Doryanthaceae), right: Lobelia gibberoa (Campanulaceae).

I thoroughly enjoyed my visit to see such a beautiful and colourful garden, which did not disappoint botanically either. Mark Chase is one of the founding researchers of the Angiosperm Phylogeny Group, an international group of systematic botanists who have used molecular phylogenetic studies to revolutionise the way that flowering plants are classified at family level. Maarten also has published extensively on plant phylogeny, especially ferns, and several plant families have been named by him or together with colleagues. It was no surprise therefore to find a number of very unusual plant families growing in their garden.

Like all collectors, we plant-lovers often aspire to completing a set. A while ago, I set myself the challenge of growing species representative of as many as possible of the c. 450 families of vascular plants in the world (ferns, gymnosperms and flowering plants) in my tiny backyard. So far I have over 150 families represented. I was delighted therefore to discover that Maarten has a similar aspiration, and grows plants from a similar number of families. However, a number of the plants he grows are from families not (yet!) represented in my garden, some of which I didn’t even know if it was possible to grow in London (for example, Pennantiaceae, Aphanopetalaceae, Microteaceae, Corynocarpaceae and Sphenocleaceae). I was delighted to get some ideas for new plants/plant families to try.

Some of the more unusual plant families represented in Maarten Christenhusz garden, clockwise from top left: Aphanopetalum sp. (Aphanopetalaceae), Polypremum procumbens (Tetrachondraceae), Corynocarpus sp. (Corynocarpaceae), Haloragis masatierrana (Haloragaceae) and Gelsemium sempervirens (Gelsemiaceae).
Some of the more unusual plant families represented in the garden, clockwise from top left: Aphanopetalum sp. (Aphanopetalaceae), Polypremum procumbens (Tetrachondraceae), Corynocarpus sp. (Corynocarpaceae), Haloragis masatierrana (Haloragaceae) and Gelsemium sempervirens (Gelsemiaceae).

Plants grown for their botanical interests aren’t always the most colourful or showy, so I have also been inspired to introduce more colour to my own garden (particularly later in the season), by planting more herbaceous perennials and not being afraid to use bedding plants more to provide splashes of colour against the foliage of other plants.

Are you a botanist with an interesting garden you’d like to share on my blog? If so, I’d love to hear from you! Please contact me at [email protected]