Hedging, Jorge, Plants

alternatives to buxus

Forgoing box is a real shame as it possesses all the characteristics required for low maintenance natural hedging. It responds well to clipping, and is slow growing, often needing to be cut only once a year, with growth usually between 10 and 15cm. It is also frost resistant and native to the UK, being cultivated since at least Roman times. Sadly, due to the current box blight epidemic, box is no longer the premium option, as the disease can destroy years of work to which the gardener can do little to stop. However, using other plants can be seen as a great opportunity to experiment, which makes gardening so enjoyable in the first place. There are so many underappreciated alternatives that can produce stunning delineated gardens.

Obviously, no plant will be exactly like box and the shape (and colour) of your hedge could be very different. If you wish for a substitute for box, however, Privet (Ligustrum ovalifolium) is a highly popular choice that is extremely hardy and small leaved, although sadly fast growing; henceforth, it will need to be trimmed multiple times in the summer to encourage dense growth. As it is only semi-evergreen, there is also the possibility of the plant shedding its leaves in extreme bouts of cold. Another possibility is switching to artificial topiary that is visually identical to box, and virtually indestructible, although its shape is limited to the manufacturer’s designs.

alternatives to box

Other worthy alternatives include the Griselinia littoralis, Euonymus japonicus and Elaeagnus ebbingei. The Griselinia is notable for its soft glossy leaves, average growth rate and responsiveness to clipping. The Euonymus is usually two-tone with cream bordering the edges of its otherwise green leaves, although it can variegate greatly in full sunlight. The plant is hardy and suitable for nearly all soil types, although will need maintenance to ensure denseness. The Elaeagnus is a great alternative as it is dense, hardy and responsive to clipping. It is also fragrant in the autumn with the emergence of white flowers.

One of the best species of natural hedging has to be the Taxus baccata, commonly known as the English Yew or Common Yew; it is very hardy, average growing, dense and great for birds, which love its berries. For more colourful alternatives, lavender (Lavandula angustifolia) and sometimes heather, can be grown into hedges. Key for lavender is to cut it before it flowers, or otherwise it will lose its shape. It is great for wildlife, fragrant and evergreen.

common yew

Due to the box blight epidemic, the RHS Garden Wisley are currently trailing 25 alternatives to boxwood. The varieties that have performed well include such plants as the Kilworth Cream (Podocapus nivalis), Sunshine (Ligustrum sinense) and Tom Thumb (Pittosporum Tenuifolium). The team has found that the Podocapus versatile, and responsive to clipping; the plant itself can be described as extremely small leaved, and darker in colour than box. The Ligustrum is slow growing with vibrant yellow leaves, the Pittosporum purple and compact. Also of interest is how the Pittosporum is a source of food for animals in its native New Zealand and is thus hardy and responsive to clipping.

Do you have any experience growing hedges? We’d love to hear from you. Post in the comments below!

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Gardening, Hedging, How To, Jorge, Pest Control

treating box blight

Ever since the 1990s, gardeners have had to witness the destruction of their natural hedging projects due to the emergence of new fungal diseases targeting Boxwood (Buxus sempervirens). This has only been exacerbated with the introduction of the Box Tree Caterpillar (Cydalima perspectalis) that began appearing in gardens since 2011. (It was likely imported from the Far East in 2008.) This has affected many famous gardens and gardeners with even Monty Don witnessing the decimation of his 15 year ornamental hedge project. The blight is so deadly that the preferred option for many gardeners is to simply destroy the affected plants, as even plants that appear to recover are often destroyed with the re-emergence of the fungus. Others have abandoned Box entirely by switching to Box alternatives. However, one need not abandon box altogether as both problems are preventable and treatable, although the blight requires great time and effort to combat. Other less common problems include: Box Rust, Box Sucker, Box leaf-mining gall midge, box red spider mite and mussel scale.

Treating Box Blight

The two most serious forms of Box blight are Cylindrocladium buxicola and Volutella buxi, which often appear together. The former is highly destructive and can kill a plant in a matter of days. It is characteristic for producing discoloured leaves that are white on the underside with brown lesions on the top. In humid conditions, the fungus may result in black streaks on stems. The latter turns leaves yellow, darkening them to a shade of tan. How they enter the plant is also different as the Cylindrocladium enters through leaf cuticles in humid weather, while the Volutella requires a cut leaf surface. Both diseases are treated together with the same methods, although favourable growing conditions may allow the Box to recover from the Volutella without such an intervention.

Treating Box Blight is difficult, but can be done, although there is no guarantee of success, and it may be preferable to simply burn the affected box to safeguard the rest. Key is to prevent further contamination through disinfecting your tools, along with your clothes and boots that sticky spores can attach. We recommend that you use liquid copper to clean your tools. (It will kill the spores.) Now with the affected plant, it will need to be hard pruned in the affected areas, the branches burnt. The cut areas will then need to be treated with fungicides that contain tebuconazole or tebuconazole and trifloxystrobin. Any leaf debris should be picked up and destroyed and the top layer of soil removed and replaced. (Spores can stay in the soil for a whopping six years!) We recommend that you do not use fertiliser, as high nitrogen produces vulnerable growth. Instead, mushroom compost can be used as mulch to provide aeration and better microorganism balance. Finally, important to note is how the diseases are suited to humid conditions where air movement is restricted. Therefore it may be necessary to open up the compact framework of your box – a process known as halting clipping.

If you are unaffected by blight yet, or wish to prevent blight from entering new areas of the garden, prevention is better than adaption. When bringing in new box keep it quarantined and watch for symptoms. To do this, you can either leave it for six weeks untouched, or create humid conditions and leave it for 3 weeks. As the fungus thrives in such conditions, the blight will appear by then. (Sadly, some nurseries use fungicides to hide such symptoms, so it is necessary to be cautious.) Again, preventing humidity is key, and can be achieved through watering at the base of the plant rather than at the foliage, and by positioning the Box away from overhanging plants. Also important is not to clip when rain is forecast, or the plants wet. Finally, it is recommended that you provide adequate ventilation for better airflow, spacing the Box around 30 cm apart from each other.

A Look to the Future

buxus

For now it appears that box blight will run rampant over gardeners’ painstaking creations, but there are a number of blight resistant cultivars being developed in Europe that should appear on the market in a few years.

Treating Box Rust

Box rust (Puccinia buxi) is another common problem that affects Box and is symptomatic for orange pustules on both sides of the leaves. It is usually harmless and is treated through cutting off the affected areas or using fungicides for rust diseases such as tebuconazole, tebuconazole with trifloxystrobin and triticonazole.

Stopping the Box Tree Caterpillar

stop box caterpillar

The Box Tree Caterpillar can leave patches of dieback much like box blight, and is distinctive for patches of webbing and frass droppings. Young Caterpillars are greenish-yellow with black heads, while the older ones have thick black and thin white stripes along the body and are up to 4cm long. Like most insects, they are most active during the warmer months, but can overwinter in webbing spun between leaves. To deal with them, they can either be picked off by hand, or dealt with insecticides that include ingredients such as pyrethrum, deltamethrin, lambda-cyhalothrin, and acetamiprid. (It is recommended that you do not spray plants in flower as this could deter potential pollinators.) Like box blight, prevention is preferable to adaptation so it is recommended that you check new plants in nurseries.

Other Box Problems Caused by Insects

  • The Box Sucker (Psylla buxi) can distort your box by turning the leaves into mini-cabbages. (Oh, No!) The insects suck the Box’s sap and leave chemicals that retard new growth. It is not usually serious, but can be controlled with the above insecticides and clipping.
  • The box leaf-mining gall midge (Monarthropalpus flavus) effects Box through causing a yellowish discoloration of the leaves. This discolouration is caused by the fly’s larvae that hatch and feed inside the foliage. It is, again, unserious and not usually worth treatment.
  • Mussel scale (Lepidosaphes ulmi) are tiny mussel shaped sap-sucking insects that usually attach to bark, but on occasion will appear on leaves. Small infestations are not worth treating, but larger infestations can be treated with the above insecticides or organic sprays such plant oils. Such treatments are best applied in May and June when the next generation is emerging and vulnerable.  
  • The box red spider mite (Eurytetranychus buxi) is another sap-sucker that feeds on the undersides of leaves, causing a fine white mottling. While the mites are difficult to exterminate, they do not seriously damage the plant; the bugs can be treated with fatty acids and plant oil sprays applied continuously in five day intervals until the all the life-cycles of mites are wiped out.

Have you had trouble with box blight? We’d love to hear how you coped. Post in the comments below!

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Dakota Murphey, Garden Design, Gardening, Plants

It’s ironic that one of the most influential men in English gardening history was actually Irish. William Robinson was born in 1838, and studied horticulture at the National Botanic Gardens at Glasnevin near Dublin. As a teenager, he worked at a grand garden in Waterford, then on the estate of an Irish peer, before moving to London in his early twenties.

Gravetye Manor Hotel
Photo by Nigel Freeman

His job at Regent’s Park – looking after hardy plants and wildflowers – must have had a major influence on his gardening predisposition, and Robinson soon became a vociferous opponent of mixed herbaceous borders of hardy perennial plants and the strict, formalised Victorian gardens of planted-out bedding arrangements.

At 29, Robinson began working for the influential magazine, The Gardener’s Chronicle, and in 1871, he launched his own magazine, The Garden. He also started writing gardening books, of which The Wild Garden (1871) and The English Flower Garden were the most successful. First published in 1883, The English Flower Garden went on to become one of the world’s best-selling gardening books of all time.

William Robinson changed the face of English gardens, turning his back on the rigidity of flower garden design at a time which had, he noted, ‘thousands of plants set out in formal and geometrical array, the result, a bad carpet’. His ideas about growing hardy perennials in mixed borders to create a more natural look were radical at the time and were directly opposed to the Victorian practice of planting numerous annuals in large formal blocks. Robinson even criticised the Garden of Versailles, calling it ‘terrible’!

Robinson was most vocal against ‘pretend’ Italian and French gardens, standard roses, and other ‘tricks’ common in garden design at the time. He preferred, instead, to use close-packed plantings of perennials and groundcovers that expose no bare soil; alpine plants in rock gardens; and the liberal use of native plants and hardy perennials. These ‘wild’ plantings furthered Robinson’s ideas of a garden being one that blends into the larger landscape of the water’s edge, the meadow and the woodland.

In 1884, using income and royalties from the magazine and his books, together with money from some property deals, Robinson bought Gravetye Manor, an Elizabethan house and farmland near East Grinstead in West Sussex. This is where he lived until his death, planting, experimenting, writing and acquiring more land – eventually he owned more than 400 hectares.

Much of the estate had been managed as a coppiced woodland in which Robinson planted huge drifts of cyclamen, scilla and narcissus (in 1897 alone, he planted somewhere in the region of 100,000 narcissi). On the edges of the woods, and in cleared spaces, he oversaw plantings of lily, Japanese anemone, pampas grass and acanthus, together with hundreds of shrubs such as stewartia, nyssa, and fothergilla.

In flower beds closer to the main house, he planted red valerian, which he allowed to spread naturally around paving stones and staircases. Under the trees that surround the lake, he planted thousands of daffodils that in spring present a truly amazing sight.

William Robinson
Photo courtesy Gravetye Manor Hotel and Restaurant

In the first chapter of The English Flower Garden, Robinson compared gardening to art, and wrote: ‘The gardener must follow the true artist, however modestly, in his respect for things as they are, in delight in natural form and beauty of flower and tree, if we are to be free from barren geometry, and if our gardens are ever to be true pictures. And, as the artist’s work is to see for us and preserve in pictures some of the beauty of landscape, tree, or flower, so the gardeners’ should be to keep for us, as far as may be, the living things themselves.’

In 1899, Robinson extended the house, adding stone walls which were the perfect backing for perennial beds and a formal garden. A short distance below the house, he created a wildflower meadow and also planted hundreds of trees. Among these is a handkerchief tree (Davidia involucrata), which is one of the oldest and largest in Britain.

The extraordinary walled vegetable garden he created is oval-shaped, south-facing, and covers an area of nearly 1 hectare. Walled gardens are known to be substantially warmer than the ground outside and at Gravetye the difference is around 3-4 degrees Celsius.

Unfortunately, when Robinson died in 1935 at the extraordinary age of 96, the gardens were neglected until the 1950s, when Gravetye Manor was opened as a hotel by Peter Herbert, who worked on renovating the garden until his retirement in 2004.

The new head gardener, Tom Coward, is following in Robinson’s footsteps, ensuring colour and ‘wildness’ in the formal and informal flower beds from late March until the end of October, and overseeing some much-needed restoration projects.

Garden enthusiast, Dakota Murphey, wrote this article. Working alongside one of the UK’s leading garden designers, Andy Sturgeon.

Flowers, Jorge, Plants

cherry-tree-flower-in-winter

Plants are intelligent inasmuch as they only flower when the light, age and energy conditions are appropriate to allow the plant to reproduce successfully. To do this, they have developed at least 20 different senses to monitor the complex conditions in their environment and are able to take into account factors like humidity, gravity and even electromagnetic fields. Plants differ greatly in their evolutionary strategy, and possess a diffused brain of sorts as to process information. This is why unlike, say mammals, plants are able to survive a significant loss of body mass.

Most plants flower in the spring or summer when the heat-sensitive bees are ready to facilitate conjugation with trees nearby. Spring is usually preferred because it gives the resultant fruit more months to soak in the heat and sunlight to produce fructose, which feed the sugar-crazed mammals and birds that the plant needs to spread its off-spring far from the mothership. Winter doesn’t work so well as the worker bees are otherwise occupied maintaining the temperature of the queen bee.

bluebells-flower-in-winter

Some, however, such as snowdrops and bluebells, have carved out a niche that allows them to gain a step up over their competitors. By flowering in winter, they are able to survive quite happily in real-estate that most plants can’t – that is, under the heavy bows of large deciduous trees, deep inside the ancient woods. In places where even grass can’t grow, these plants thrive as they utilise their bulbs as an energy storage device that they fill up in the early spring when the sun is weak and the trees leafless. By the time the big trees are fully-leaved, the plants have done their work for the year and their dark leaves are already dying off by the end of spring. The sugars produced by photosynthesis are converted to starch and withdrawn deep into the earth-bound bulb for protection. And by choosing this tactic – the protection of the mighty deciduous trees – they’ve avoided competing with the most ruthless of summer plants like grass.

But what of the winter-flowering trees like the Mahonia and Cherry tree? Most likely, the winter-flowering trees found just a few insects to spread the pollen. And because there were no other flowers around at the time, the winter-flowering trees had hit on a limited but good-enough niche.

mahonia-flower-in-winter

And what are the winter-pollinating insects and why do they seek out flowering-plants in winter? Recent research has shown that one of the UK’s most common bumblebees (Bombus terrestris) is achieving comparable foraging success in winter on plants such as Mahonia to that achieved in summer months. There are also a few moths that, just like many plants, have evolved antifreeze in their blood to prevent the formation of ice-crystals when the temperature falls below zero.

So, therefore just like the winter-flowering plants, insects have crafted themselves their own niches to ensure the survival of their species.

bombus-terrestris

The Science

Many plants flower in time for a particular season by responding to the length of day, a process known as photoperiodism. While scientists do not fully understand how plants do this, it is accepted that when a plant flowers is related to its genes and external environment.

In plants, scientists have identified the CONSTANS and DNF (DAY NEUTRAL FLOWERING) genes as the key mechanisms that regulate a plant’s flowering time in response to day length. In the Arabidopsis plant, scientists recently identified a faulty DNF gene that led to abnormal flowering times in mutant plants. The DNF acted to repress the activation of the CONSTANS gene until light levels rise above a certain threshold in daytime. Hence, once a functional DNF was introduced into the plant, the abnormal flowering was corrected.

In a separate study, scientists identified the sugar molecule trehalose-6-phosphate (T6P) in the Arabidopsis thaliana as playing an essential role in controlling flowering time in relation to energy reserves. As such, once a certain day length was perceived by the plant’s leaves, a mix of photoreceptors and other proteins would lead to the expression of the FLOWERING LOCUS T (FT) gene that would migrate proteins to the tip of the shoot, triggering the expression of flowers. However, as a failsafe, once the plant reaches a certain age, it would begin to flower anyway regardless of day length. As flowering is an extremely intensive process for the plant, energy too must also be available in the form of sugar. Here, the T6P sugar molecule would act as a signal for energy levels, regulating the production of FT protein. Thus, the T6P acts to influence both of the two most important pathways to flowering – the expression of the flowering gene and the production of the flowering protein.

Ultimately, greater understanding of the complex pathways that control flowering times will allow farmers to reduce uncertainty and thus boost their agricultural output.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

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