For many who visit gardens all around the world it is the lure of the cultivated plant which exerts an irresistible pull. The heavy headed hybrid rose is forgiven all its exhaustive and outlandish cultural requirements in exchange for one brief moment of delicious scent. Yet, those plants which persist uninvited, with little fuss or attention required, remain not only maligned but often overlooked altogether. However, to members of both the Birmingham and Black Country Botanical Society and the Warwickshire Flora Group, these resilient plants, lurking in the background, excite loyalties far beyond those inspired by the latest garden centre fad. Responsible for mapping the spontaneous flora which occurs in the local region, volunteers from both societies, led by local expert Mike Poulton, recently visited Winterbourne to record those species which had been spared the horror of the garden hoe.
Botanical surveys are conducted with the aim of monitoring changes and local migrations of the nation’s wild flora. Particular attention is paid to rapid fluctuations in population numbers and those non-native species which have the potential to become invasive. Any location within a given area can yield an abundance of native flora but it is often the unlikeliest of places which proves the happiest hunting ground for the botanist. Land which is regularly disturbed, where dormant seed is brought to the surface of the soil, such as in allotments and abandoned industrial and housing estates, can produce a surprising array of botanical diversity.
“Some botanists are motivated by searching out rarities and travel to all parts of the British Isles in their quest. These are known as plant twitchers as opposed to bird twitchers! However, a great deal of satisfaction is gained from carrying out a comprehensive survey of a particular site. It can also be very rewarding keeping an accumulative list of plants that occur at a local site in which you live.”
Mike Poulton, Birmingham and Black Country Botanical Society
Surveys are usually conducted according to the grid references of an Ordnance Survey map or, where localities are smaller, monads (1km squares). Fortunately, Winterbourne itself is conveniently located in a single monad and was chosen as a suitable site to survey for several reasons but primarily because the gardens contain plants from all over the world which have the potential to naturalise and compete with native flora. There are many examples of this kind of naturalisation occurring at Winterbourne. Indeed, visitors are greeted by one such pioneer immediately as they enter the garden. Erinus alpinus (fairy foxglove) grows naturally in the brickwork surrounding the main gates. This is a local migrant from the nearby Scree Garden installed by Winterbourne’s final private owner in the 1930s.
Distinguishing between cultivated and non-cultivated plants is not always easy, particularly in a garden setting such as Winterbourne, where even the weeds are likely to be neophytes (non-native plants introduced to this country post 1500 AD). Many botanists dispute exactly where the line should be drawn; some argue that any plant occurring spontaneously of its own accord should be recorded. Others argue that only those species which demonstrate the ability to establish a substantial population should be considered.
It is in fact the neophytes which are often the most revealing. The final species list for Winterbourne can be interpreted in part as a history of the garden itself; tracery evidence of over 100 years of horticultural experiment. Many of the species recorded were once cultivated intentionally. Some, such as Lysichiton americanus (skunk cabbage), which now runs rampant through the wet woodland areas of our garden, were planted as exotic ornamentals before it was understood how invasive they were likely to be.
Others, such as Solanum chacoense, have resulted from simple academic curiosity. This diminutive relative of the potato was introduced to the gardens by Jack Hawkes, a former Mason Professor of Botany at the University of Birmingham, who specialised in the genetic diversity of potatoes, and grew many species at Winterbourne. Commonly referred to as the chaco potato, this aggressive weed of South America, is known locally as the Prof Hawkes potato weed and has been considered ineradicable by garden staff for decades who find it growing at the base of hedges and fences often beneath the shelter of other plants.
“A x10 hand lens is essential for someone who wants to take botany seriously. A hand lens enables the user to examine parts of a plant that are not visible to the naked eye, an essential tool in the naming of some plants. A small pair of secateurs can also be useful for taking samples as can plastic bags in which to keep them fresh. Plants should never be uprooted! There are very few instances where the roots of a plant are necessary for identification.”
Mike Poulton, Birmingham and Black Country Botanical Society
Not all wild flowers are equally as obscure. Many are instantly recognisable to even the most casual of naturalists. Our native foxgloves and bluebells, for example, constitute part of a shared memory formed and established in childhood. However, even those which appear most commonly, can hide deceptively difficult identification traits. Vigorous weed species such as willowherbs are in fact sometimes near impossible to discern from one another; there are potentially 200 species of Epilobium (willowherb) alone.
Some botanists choose to specialise in one or more of these critical groups. By sending a specimen to a specialist it is often possible to have these tricky plants identified. Such expertise was necessary to confirm the identification of a plucky fern found growing between the mortar of an exterior wall of our Gilbert Orchid House. Dr Fred Rumsey of the Natural History Museum confirmed the specimen as Pteris vittata (ladder brake). Usually associated with limestone habitats, this tropical species can often be found growing spontaneously in concrete cracks in its native Australasia, Africa and Asia. However, it is known only to have escaped the relative comfort of a glasshouse in three other locations in the UK; the Chelsea Physic Garden, The Royal Botanic Gardens, Kew, and the University of Oxford Botanic Garden.
“The standard work used by an experienced botanist is ‘Stace, New Flora of the British Isles – Third Edition’. However, this is a heavy book to take out into the field! There is no one book in particular that I would recommend for the beginner. However, ‘The Wild Flower Key’ by Francis Rose, updated by Clare O’Reilly, and ‘Wild Flowers of Britain and Ireland’ by Blamey and Fitter are a good choice as both are very descriptive and have very good illustrations.”
Mike Poulton, Birmingham and Black Country Botanical Society
With so much of Britain’s wild flora being appraised by the gardener only as it is removed from the flower border, the horticulturalist and botanist can often appear pitched in irreconcilable conflict. Yet Mike Poulton believes that his own experience as both a professional horticulturalist and expert botanist has served to deepen his understanding of both disciplines in ways which can help bring each closer together.
Mike began his career as a Propagator Gardener for the Central Birmingham Health Authority but his love of plants was fostered much earlier whilst still a child reading an edition of ‘Collins Pocket Guide to Wild Flowers’. In this book the degree to which any one plant was considered rare was denoted by the number of stars which appeared alongside its name. Mike’s inevitable hunt for his first three-star rarity eventually led to a passion for exotic cultivated plants. However, this passion, and his later career, arrived not before he had learnt a proper appreciation for all things small and ‘insignificant’ which make up the greatest part of our native flora.
In an urbanised world, as genuinely wild spaces become ever smaller, the gardener increasingly finds himself at the vanguard of urban conservation. Improved methods of cleaning seed and overuse of herbicides mean that some of these ‘insignificant’ weeds have all but disappeared. Of course, the many garden plants which provide us with so much pleasure need not be cultivated at the expense of wild flowers. Certain spontaneous arrivals can be re-imagined not as a weed to be removed but a welcome addition to a more fluid and evenly balanced garden environment. In this hybridised ‘new wild’, the garden fence becomes not a barrier between the garden and an ever diminishing natural world beyond it, but a welcome refuge in which vulnerable species can flourish, in combination with more traditional garden varieties, safeguarding both against future decimation.
Click here to find out how you too can visit Winterbourne and discover part of Birmingham’s rich flora for yourself.
gardentourist
‘New wild’, inspiring approach to deal with cultivated and not cultivated plants. Thank you, also for the book tips.
Winterbourne House and Garden
Not a problem Erica, we hope you find them fun and useful! Lots of people seem to have particular ‘weeds’ which they allow to naturalise on their plot. Geranium robertianum is a popular natural invader to let colonise bare spaces where they appear. Perhaps you and other Mini-Diggers have a favourite wild flower which is welcome in the back garden?
Oddment
It’s impossible not to cheer for the “plucky fern,” and equally impossible not to be charmed by the name “plant twitchers.” An amazing overview of the Winterbourne monad.
Winterbourne House and Garden
Hello Maureen. It is nice to be in the same company as Kew Gardens et al. The Pteris is doing well, shows no sign of shrinking from the British weather and has even produced a couple of babies!
Marian St.Clair
Day to day, in my own landscape, the neophytes I’m most likely to notice are the unwelcome species in the wild garden along the river which floated in on floodwaters and then established a toehold in alluvial soil. Japanese stiltgrass (Microstegium vimineum) is the worst and there is no hope of irradication. With persistance, progress has been made with Japanese knotweed (Fallopia japonica), though I’m not sure to what end, as it persists on either side of the property. On a happier note, the ornamental garden offered a few unknown bulbs I was happy to adopt. If only all surprises, such as your lovely fairy foxglove, could be as welcome.
Winterbourne House and Garden
Hello Marian. Thanks for stopping by. It will give you little satisfaction we’re sure to know that we also suffer from Japnaese knotweed. Bindweed and Himalayan balsam are also persistent guests – no matter how many times we hint that perhaps they should leave! As you say, for every thug, there is always a welcome surprise. Talking of bulbs, the cornered leek provides us with a good spring show every year. It does spread like mad but has such lovely, delicate flowers it cannot be anything but admired.
Liz Riley
Hi Winterbourne,
A topic close to our hearts as we garden within a World Heritage Natinal Park! There are many exotics now deemed weeds in the Blue Mountains and many more designated as sleeper weeds. While we try and increase the biodiversity of our heritage exotic garden we are ever mindful of this sleeper potential. One tactic I am currently working on is to improve the soil quality sufficiently inside the garden walls so that we can grow exotics inside that would not thrive outside. Naturalised weeds within this garden that we are deciding to live with are the native Pratia purpurascens and the exotic wild strawberry. A weed we continue to battle with is onion weed (Nothoscordum iodorum). Forget-me-nots and bluebells are both extremely weedy in this garden in that they compete strongly and displace other plantings. They are both greatly admireded by visitors.
We do have sections of the garden dedicated to native plants with the aim of increasing the native biodiversity of the urban environment.
Liz
Winterbourne House and Garden
Hello Liz. Thanks for getting in touch. You’re garden sounds wonderful as always… even the weeds! We also struggle with thuggish Onion weed and Pratia in the UK. Although, Nothoscordum x borbonicum and Pratia pedunculata are the two most commonly found species here. Bluebells and forget-me-nots of course also arrive whether we want them to or not – lots of people couldn’t imagine an English garden without them!
Chloris
A fascinating post, thank you. I love the little fairy foxglove and I wish the skunk cabbage was a weed in my garden.
Winterbourne House and Garden
Hello Liz. Thanks for taking the time to comment. We’re glad you enjoyed reading about some of our more unusual interlopers! It was officially the first day of autumn yesterday but the usually tropical Pteris is still showing no sign of panic!