Container Hort.

Anagallis monelli ‘Skylover’ is a good plant with which to introduce blue into summer containers, making a change from the hanging basket and window box standard Lobelia in its upright and trailing forms. The intensely blue star shaped flowers of Anagallis repeat flower for months and the dense foliage is almost succulent in its habit. The common name of this plant is Blue Pimpernel but there was nothing elusive about the consistent display it provided last summer when I used it in the three troughs on the south facing bay window of the house.

Less successful was my attempt to plant it with white ivy-leaved Pelargonium which struggled after a month or so. I believe the combination would have worked better in larger containers. For next year, I have my eye on the window box version of the dark grey recycled plastic containers I mentioned in my blog post dated 26 October 2018, ‘Weeds Roots & Leaves is out front’. I feel the deep classic boxes will bring a contemporary accent to the front garden as well as providing a much larger planting area for a more adventurous summer scheme. A small lavender in the central trough was also overwhelmed by the vigour of the newcomer. Despite this, I shall certainly plant Anagallis again, because apart from its beautiful colour it required little or no dead-heading, maintenance consisting of a daily watering and a weekly dose of tomato food. I bought the six plants as small plugs from Suttons. They arrived in early April and I potted them on into larger pots for a few weeks before planting out in May.

*Anagallis monelli* ‘Skylover’ with white *Pelargonium.* Detail from window troughs summer 2018.

This winter I have planted the bay window troughs with a mixed scheme of large flowered ‘Cadbury’s purple’ pansies, Bird’s Foot ivy (Hedera saggitifolia), Golden Japanese Rush (Acorus gramineus Ogon) and White Sea Campion (Silene Druett’s Variegated). The slim leaves of blue Grape Hyacinth (Muscari armeniacum) are already emerging, a tantalising preview of the further layer of colour to come in early spring.

I have already decided that another element of the scheme next summer for the terracotta pots on the patio in the sunniest corner of the garden and in a pot beside the front door will be a particular shade of ivy-leaved Pelargonium. Of the many exquisite garden images in the Royal Academy’s exhibition ‘Painting the Modern Garden: Monet to Matisse’ in 2015, I found one of the simplest the most memorable. Highlighted against a dark green background, a swag decorated terracotta pot stands atop a plinth at the foot of a stone staircase, warm toned salmon pink pelargoniums spilling down beside the steps. The painter is Spanish impressionist Joaquin Sorolla, in whose courtyard garden in Madrid the canvas was painted. I was thrilled last week to read, thanks to a Madrid based friend’s Facebook post, that the National Gallery is to stage an exhibition of Sorolla’s work from 18 March to 7 July next year, ‘Sorolla: Spanish Master of Light’. Whether this canvas will be included I do not know, but I do hope that at least one of the 60 plus paintings in the show will feature his beautiful garden.

Salmon pink geraniums (Pelargonium) also take centre stage in a book I read as a child, ‘The Little White Horse’ by Elizabeth Goudge. Why I have recalled these particular plants so vividly for all these years I cannot fathom, but the description of a West Country garden in which these flowers proliferated, still resonates. Another plant from the book will also feature in my container planting next summer. A principal character in the magical story is Miss Heliotrope and scented purple heliotrope (Heliotropium) will act as a perfect foil for the brighter coloured geraniums.

Autumn tasks at Osterley influence garden assignments

A colourless sky lowered over the gardens at Osterley last Friday, serving to highlight the intensity of the colour of the autumn leaves still clinging to the trees in the gardens and park and those carpeting the ground. Our morning task was to sweep the leaves from the lawns surrounding the mature oaks between Mrs Child’s Flower Garden and the path leading to the Winter Garden. Having filled our barrows, we deposited the golden haul on a new leaf pile on the site of the rich dark cliff face of leaf mould which we mined earlier this year to mulch one of the four large beds in the Tudor Walled Garden.

In the afternoon we worked in an area of the garden between the lake and the wider parkland where a stretch of the fence between garden and park needed to be cleared of brambles. Protected by elbow length red suede gauntlets, and using mattock and spades to sever the stubbornest roots, in two hours our working detail of five volunteers cleared the tangle of brambles from either side of the fence as well as a prickly patch at the foot of the nearby Ice House Mound. As with all weeding it is so satisfying to excavate as long a root as possible without leaving anything behind to emerge stronger than ever next year.

Heading back to the Gardener’s Bothy with barrows of brambles

Our work on the previous two Fridays was slightly more sedate. For example we planted two lowish growing cultivars of Allium bulb beneath the roses in the Cutting Garden: the yellowish green flowered ‘Moly’ and the rose pink ‘Unifolium’ or American Onion. Later, on the bank opposite the American Border, we lifted and replaced divots of turf into which we posted two species of spring flowering bulbs. Both were familiar from Visitor Information team days at Royal Botanic Gardens, Kew when we were often asked to identify the canvas of bright blue starry flowered Chionodoxa forbesii on the triangular lawn near White Peaks cafe with Kew Palace as its backdrop. The path further along from this part of Kew is called Princess Walk where the early flowered Crocus tommasinianus reveal themselves in February. The cultivar we planted at Osterley the other week was ‘Ruby Giant’ which is described on the RHS website as having reddish purple flowers. The squirrels which frequent that part of the garden kept a close eye on our activities and I do hope they find plenty of other naturally available nourishment and do not unearth the treasures we buried.

Planting in the Winter Garden on 9 November included a ribbon of Stipa tenuissima between contrasting tufts of lower growing ornamental grasses, the crowns of which we cleared thoroughly of Field Bindweed, Convolvulus arvensis, as well as less pernicious weeds. In another section of the Winter Garden, other colleagues planted a drift of strap-leaved Hart’s Tongue ferns, Asplenium scolopendrium. Nearby several different species of dogwoods, Cornus, have shed most of their leaves revealing glossy stems shaded from orange-gold, crimson and purple through to almost black, demonstrating why this part of Osterley is a colourful and interesting area to visit throughout the winter months.

Weeds Roots & Leaves has refreshed a local back garden during three days’ work over the last few weeks and I planted three Cornus alba ‘Elegantissima’ in the 1.5 metre deep border I created at the rear of the site. I chose this cultivar both for its red stems in winter to contrast with the surrounding evergreen shrubs and for its cream edged leaves in spring and summer to bring an impression of dappled light into a shadier area of this largely sunny garden.

By coincidence a cultivar of another species of plant which is a dramatic feature of Osterley’s Winter Garden at this time of year turned up in a new client’s garden which I visited at the weekend in preparation for carrying out some seasonal maintenance work this week. Clematis cirrhosa ‘Freckles’ scrambles to the top of a tree in the central section of the Winter Garden forming a cloak of toothed foliage and pale yellow bell shaped flowers heavily speckled inside with maroon becoming a mass of silky seed-heads when the flowering has finished. While carrying out a quick inventory of the plants in the client’s garden we found, on the west-facing wall of the house, an exquisite specimen not unlike Osterley’s ‘Freckles’ but with more finely cut leaves and slightly less speckled flower interiors. After a short online search I identified this as C. cirrhosa var. balearica which is also known as fern-leaved clematis, an evergreen the interior of whose creamy flowers are spotted purple. I have read that the flowers are slightly fragrant and am looking forward to having a sniff when I start work at the site tomorrow.

Volunteering in the garden at Osterley is always very enjoyable and doubly so when it informs the work of Weeds Roots & Leaves. As well as planting ideas and shared knowledge about the poisonous properties of some plants, I am, for example, so grateful for the information about a couple of wholesale nurseries which I would have known nothing about without the generous recommendation of a fellow volunteer.

Very like a hedge

Being able to combine a love of plants with a love of words is for me one of the side benefits of gardening. Few weeks pass without my learning a new plant name, Discovering an expression for a hitherto unknown garden feature is a rarer occurrence, but this was my experience when leafing through a copy of Tim Newbury’s ‘Garden Design Bible’. In a section about planning a family garden I found an illustration of a ‘fedge’- a portmanteau word to describe a combined fence and hedge. Its purpose is to create a sturdy physical barrier where something more attractive than a plain fence is needed. The book suggests a variety of evergreens to plant alongside the wire netting fence, such a yew, Taxus baccata or Lonicera nitida, the tiny golden-leaved member of the honeysuckle genus whose appearance is more box than woodbine. Evergreen climbers, especially ivies, are recommended for tall narrow ‘fedges’ where ground space is limited.

A very substantial ‘fedge’ outside West Thames College in Isleworth: iron railings and privet

Discovering ‘fedge’ prompted me to research if there are other portmanteau words, where parts of multiple words are combined into a new word (think ‘smog’, ‘motel’ and, if you must, ‘Brexit’), in use in the horticultural world. This lead me to the practise of ‘permaculture’ which I confess I had heard of but not understood until this week. The word was coined in the 1970’s, as a marriage of ‘permanent agriculture’ and refers to any system of sustainable agriculture or horticulture that simulates features of natural ecosystems. One example of permaculture is where different layers of vegetation in a garden mimic nature and can be exploited to create a ‘food forest’. This might consist of up to seven recognised layers, with a canopy of tall trees at the upper level, descending through an understorey of lower, possibly fruit-bearing, trees, a shrub layer of berry bushes and a herbaceous layer of plants which die back in winter, including culinary and medicinal herbs. Beneath these four layers lie a ground cover layer which grows close to the ground and a ‘rhizosphere’ of roots within the soil which in the productive garden can include root crops and edible tubers, such as carrots and potatoes. The seventh layer is a vertical layer of climbers such as runner beans or vines. A panellist on the radio garden show ‘Gardeners’ Question Time’ broadcast on 9 November 2018 favoured this method of raising food crops above the conventional one or two layer allotment plot.

Perhaps a fine Quince tree such as this specimen at Osterley might form part of the understorey of fruit trees in a ‘food forest’?

I am two thirds of the way through freshening up a local back garden and two of the plants I have used in the planting scheme share the species epithet ending ‘oides‘. This means that the plants resemble another plant in some way and I suppose might be translated as ‘like’ or ‘ish’. The first of such plants is the evergreen climber Trachelospermum jasminoides, which I have planted near the house so that its jasmine-like scent will drift through the windows on summer evenings as well as perfuming the seating area around the rear of the property. One common name of the plant is intriguing: Confederate jasmine. Until I dug a little deeper I assumed it derived its name from the slavery supporting states in the American Civil War and imagined it entwining the classical pillars of southern plantation mansions such as Tara in ‘Gone with the Wind’. I understand it grows well in the southeastern states of the USA but because the plant originates in Southeast Asia, it is named for the confederacy of Malay states. The other common name of Star jasmine accurately describes the appearance of its waxy white five petalled flowers which contrast beautifully with the small glossy pointed leaves.

In the sunniest flowerbed in the garden I have underplanted a Ceanothus ‘Puget Blue’ with another ‘ish’ plant, Ceratostigma plumbaginoides. The intense blue flowers of this low-growing shrub, which appear in late summer, bear a resemblance to the flowers of the tender climber Plumbago. The common name of both plants is Leadwort but it does not seem to be known definitively whether this refers to their lead-blue flowers, the property of the sap which stains the skin a lead-blue hue or the belief of the Roman author and naturalist Pliny the Elder that leadwort cured lead poisoning. Whatever the derivation of Ceratostigma plumbaginoides‘s tongue-twister of a name it is ideal ground cover in sunny sites and noteworthy for the glorious reds and oranges of its deciduous leaves in autumn. Bill Neal’s ‘Gardener’s Latin’ recommends underplanting it with small bulbs which can flower while the leadwort is dormant in the early months of the year, the dying foliage of the bulbs then disguised by the little shrub’s emerging leaves. This advice pre-empts my agenda for next week’s session in the client’s garden when I plan to plant diminuitive Narcissus ‘Jet Fire’ in the bed in which I’ve put this anything but leaden plant.

Next time I report upon recent planting sessions at Osterley House and Gardens and reflect on my second professional gardening assignment.

Oh no, knot another weed!

In the 80’s, 90’s and noughties, when the author’s life was more ‘Reads Books & Deeds’ than ‘Weeds Roots & Leaves’, the nearest a property lawyer came to horticulture when acting in the purchase of a house, was to enquire of the seller’s solicitors if that large tree in the garden was the subject of a Tree Preservation Order. Since 2013 it is standard practice for the seller of a property to declare whether Japanese Knotweed*, Fallopia japonica, is present on the property in the Property Information Form. This means that it is the seller’s responsibility to check the garden for this invasive weed and if it is present to provide a management plan from a professional eradication company. Once a buyer’s solicitor has noted the presence of the weed when checking the form, and has notified the lender, the latter is likely to seek assurance that it will be eradicated, in the form of a management plan, before agreeing to fund the transition. Failure to disclose the presence of Japanese Knotweed or the lack of a management plan will delay the sale and increase the cost of the buying process or, the worst case scenario, give rise to a potential misrepresentation claim.

How has a plant introduced from the Far East in 1825 as a garden ornamental, and praised by innovative William Robinson in 1879 as ‘one of the finest herbaceous plants in cultivation’, developed a reputation as a possible property deal-breaker? Had Japanese Knotweed confined itself to the garden, the story would have ended here, but it escaped from gardens to establish colonies beside railway lines, waterways, roadsides and on waste land. By shielding lower growing species from light with its dense canopy it obliterates local native vegetation and its fallen leaves form a dense mulch to suppress the growth of any incipient seedlings. In the UK it spreads not by seed but by a huge rhizome system, impervious to many herbicides and needing a saw to sever the rhizomes. I can understand why our gardening forebears liked this plant- it has an attractive and exotic appearance with up to 2 metre tall bamboo-like stems speckled purple, heart shaped leaves about 15cm long and sprays of small white flowers. It would fill a shady corner very satisfactorily were it not for its thuggish tendencies.

As well as competing with native species, it contributes to river bank erosion and increases the risk of flooding. In a residential or commercial property context, it can cause structural damage by forcing itself through paving and concrete foundations. Indeed under the Environmental Protection Act 1990 Japanese Knotweed is classified as controlled waste. This means that a property owner must prevent it from spreading into the wild and causing ecological damage. If it discovered on a property it does not have to be removed but the property owner can be prosecuted for allowing it to spread onto someone else’s property and will understandably wish to find a satisfactory means of control. The bad news is that such means are both drastic and expensive. A few examples follow:

Spraying, over a course of at least three years, with chemicals that are approved herbicides, until the underground rhizomes become dormant.
Burying the waste at a depth of at least five metres (!), having first sought the approval of the Environment Agency.
Arranging for the waste to be carried off-site by a registered waste carrier to be taken to an authorised landfill site.

Needless to say, bio-security precautions are essential when dealing with this species and tools, boots and gloves require thorough cleaning and disinfecting after handling Japanese Knotweed to prevent pieces of plant material escaping and forming a new problem-laden clump. One recommendation I have read for how to deal with Japanese Knotweed is to move house! In light of the issues I have mentioned during the conveyancing process this may be easier said than done.

Before I move onto a more positive member of the knotweed family, I have seen the damage that an invasive plant can do to a building. In this case not Japanese Knotweed but the Tree of Heaven, Ailanthus altissima, whose roots had penetrated the foundations of a local church at the point where the wall of the building met the neighbouring path. I saw the plant material growing between the floor tiles inside the church! The tree, which was beautiful but unsuitable for planting so close to a building, has now been removed, but only after a protracted negotiation with the local authority.

Japanese Knotweed is a member of the knotweed family, Polygonaceae, which also contains the genus Persicaria. I planted a species of this plant in my garden earlier this year and I believe it is Persicaria amplexicaulis, or red bistort, I rescued it (with permission) from the ‘muddy clumps’ heap near the gardeners’ bothy at Osterley, a sort of holding area where discarded plant material is put before the garden team decide whether to compost it or use it for propagation. Although it did not flower until September, it put on a lot of vegetative growth during the summer, and has withstood a couple of overnight frosts and is still going strong this first week of November. The Royal Horticultural Society describe the plant as a robust, clump-forming, semi-evergreen perennial. All good qualities but I anticipate it might one day grow too large for this small garden. In the meantime I shall enjoy its narrow spires of reddish pink flowers atop a crown of pointed mid green leaves measuring 25cm with a slightly puckered appearance.

I am charmed by the idea that Persicaria hails from the Himalayas and can imagine it forming an understorey for Rhododendrons and Camellias on the mountains’ lower slopes. Quite a leap to a suburban garden, but the same can be said for many of our now familiar garden plants which originated thousands of miles away. And it reassuring to know that not all the plants under the knotweed ‘umbrella’ create a headache for the conveyancer.

Useful information about Japanese Knotweed and how to control it and dispose of it can be found at gov.uk and at RHS