In the spirit of stepping outside my comfort zone to do something I have not done before, I joined other volunteer gardeners at National Trust Osterley this summer to deliver guided tours of the gardens. Once, sometimes twice a week, two of us led a group of up to 15 visitors through gardens which reflect the history of the house, from its origins in Tudor times, through its elegant Robert Adam makeover in the eighteenth century to today’s innovations, pausing on the way to mention the garden’s role in the Second World War.

As the season changes and we plan to alter our itinerary to take in parts of the garden designed to look at their best in the winter and early spring, I invite you to join me in this post on a virtual early autumn walk through Osterley’s gardens. You start your tour at the rear of the house, at the top of the elegantly curving double staircase facing the park beyond the garden, which Henry James (a weekend guest at the house in the late nineteenth century) describes in the opening passages of his novella, ‘The Lesson of the Master’. The hero Paul Overt, a writer, stands in the same position and observes that the steps ‘descended from a great height in two arms, with a circular sweep of the most charming effect’. He also commented on ‘the expanse of beautiful brickwork that showed for pink rather than red and that had been kept clear of messy creepers by the law under which a woman with a rare complexion disdains a veil’. From this vantage point you can see a classic feature of an eighteenth century landscape garden: bucolic pastureland framed by specimen trees, the pasture grazed by the neighbouring tenant farmer’s Charollais cattle. Before the scene we see today was created, John Roque’s immensely detailed map of London of 1741 showed three avenues of trees radiating from both the front and back of the house. This device is known as a ‘patte d’oie’  or goosefoot. The avenues have long gone save for two oak trees which once formed part of one such avenue.

Trees feature throughout our tour. Let’s descend the steps and head to the shade of the Oriental Plane tree which was planted in 1755. One of my fellow guides describes this huge tree as a grand old lady resting on her elbows, a reference to the gnarled limbs which swoop down to the ground to shade the path to one side. Look up into the leaf canopy and spare a thought for we volunteer gardeners when over the next couple of months we shall sweep up and gather the leaves to deposit in the leaf pile on the boundary of the garden. In a couple of years time we shall use the ensuing leaf mould as a winter mulch to the beds and borders in the garden so as to maintain moisture and improve the texture of the soil.

Come with me now to ‘Dickie’s Border’, the symmetrically arranged three layered shrub border named after Dickie Denton, the last Head Gardener before the property was gifted to the National Trust in 1949. His nickname was ‘TickTock’ because he was tasked with winding the clock in the Stable Block each morning. In the middle layer of planting compare the red dimpled globular fruits of the Strawberry Trees (Arbutus unedo) with the developing catkins of the Silk Tassel Bushes (Garrya elliptica). A variegated form of Rhamnus alaternus is the third shrub at this level. Alternating Magnolia grandiflora and Loquat trees (Eriobotrya japonica) provide a dark evergreen backdrop, whilst at waist height you can see shrub roses, rosemary and the gold margined leaves of Daphne Odorata aureomarginata. 

Our next stop is Mrs Child’s Flower Garden where you have a perfect view of Robert Adam’s recently restored white stucco decorated Garden House which stands at the heart of the ranks of curved flowerbeds planted for spring and summer interest. Here tall Verbascum tower candelabra-like over Salvia sclarea, Maltese cross (Lychnis chalcedonica), Centaurea Montana to name only a few of the intriguing plants to be found in these beds.  The grounds here were used at the beginning of the Second World War for training the forerunners of the British Home Guard in guerrilla tactics and house to house fighting. Led by a left-wing writer, Tom Wintringham, they were described by MI5 as ‘the bunch of socialist revolutionaries at the end of the Piccadilly Line’ and soon afterwards the operation was closed down and the park used for food production as part of the war effort.

As we walk towards our next stop please take a look at the four beautiful and unusual trees near the brick wall: Foxglove trees, Pawlonia tomentosa, and do mind your head on their low-hanging seed cases which develop from the spires of bluish mauve bell-shaped flowers which the trees bear in April. Other trees to note here include weeping limes and a Tulip Tree (Liriodendron tulipifera) and nearest the path take a look at the unusually lobed leaves of the Sassafras albidum, whose roots flavour Root Beer, and which this week is glowing with a rainbow of autumn shades.

Let’s proceed to the Picking Garden, where the flowers are grown for the 65 floral arrangements which decorate the house each week. As well as several members of the Daisy family: Heleniums, Shasta daisies and Cosmos, you can also see a row of Pot Marigolds (Calendula). These are the symbol of Childs Bank, associated with the family which owned Osterley. The variety chosen this year is Calendula ‘Radio’. You can tell from its name that this is a modern cultivar. Whilst the species of plants in this part of the garden are era authentic and would have been available to an eighteenth century gardener, their cultivars tend to be more modern and are chosen for reliability and resilience to pests and diseases.

Now we move to the main section of the Tudor Walled Garden which is laid out into four large central beds. In the bed devoted to brassicas you can see the latest member of the garden team, Harry the Hawk, whose job it is to scare pigeons from the cabbages. The next two beds are planted potager style with both ornamental and edible plants and are designed to look at their best in late summer and early autumn. Dahlias feature strongly as do Cleome (the Spider Flower), gladioli and nicotiana. Chard and amaranthus provide the edible element of these beds and at the corners of the beds you can see pyramid shaped supports to which cling the deep purple morning glory, Ipomaea ‘Grandpa Ott’. In the centre of the beds look out for the tall Castor Oil plants, Ricinus communis,  with their spiky pink flowers and large hand-shaped leaves. This plant played a key role in a tale of international espionage from 1978 when the Bulgarian dissident Georgy Markov was murdered in London with an umbrella the tip of which contained a pellet of the deadly poison Ricin which is derived from this plant. The fourth bed is planted almost exclusively with vegetables and salads. At this late stage in the season the various beans have been harvested and their supports removed, but turnips and beetroot (both red and golden) abound as do aubergines and salad leaves.

Our virtual tour is almost over. I shall leave you at the far side of the walled garden, beside the Long Border and point out to you the enormous specimen of the climbing rose Rosa banksiae and ask you to imagine a curtain of pale yellow blooms in April: it is one of the earliest roses to flower. It is named for Joseph Banks, who accompanied Captain Cook on the Endeavour, and on his return advised George III on the creation of a botanic garden at Kew. There is a local connection too, as Banks lived at Spring Grove House about half a mile to the south of Osterley. What remains of his house now forms part of West Thames College. Before we part, consider this: the Osterley site was once slated as a possible site for a national exhibition centre. Thankfully a site near Birmingham was chosen for the NEC enabling us to enjoy the gardens as they exist today. Thank you for joining me today and do come back on another occasion to see the American Border and the Winter Garden.