Persicaria runcinata ‘Purple Fantasy’. Photo: Gary Newell
Exotics are exciting again, says Gary Newell, as an updated version of the jungle garden style gains popularity for small urban spaces
The idea of naturalistic plantings is seductive, but replicating wild colonies is not an option for every outdoor space. For small and city gardens, broad wildflower meadows or extensive perennial planting are simply not practical. So it should be no surprise that recently, under the buzz of the city lights, the much-denounced urban jungle style has begun to find its feet again.It was last seen among the tree ferns of the 90s, when there was an influx of affordable plant material from European exporters, much of which was of poor quality. Coupled with the general lack of understanding for the plants and style in question, this led to failure on a grand scale, giving jungle planting a bad reputation.
Exotic gardens will always have a place in the hearts of the dedicated few, but I believe a wider renaissance is on the cards. Looking at recent show gardens at RHS Chelsea and Hampton Court, it is obvious many designers are harking back to elements of the look, or at least investigating a more exotic range of plants.
Plectranthus ciliatus. Photo: Gary Newell
The reasons for this resurgence are many. Jungle planting offers the perfect plant palette for small urban spaces, thanks to the ease of creating successful combinations, which fill spaces quickly with their high-impact foliage and bold colour clashes. City gardening demands that gardens naturally become inward looking, and the dense planting and layering in exotic schemes helps create a cocoon. This transforms tiny backyards into spaces filled with mystery, and with deceptive spatial qualities.
Another attractive quality of this style is that it features predominantly foliage-based plants which are relatively low maintenance and quick to establish – ideal for instant installation. Many of these plants are also adapted to handle the humidity and heat-island effect in the urban environment, and likely to become top choices to manage encroaching climate change.
The foundation of this style is primarily based around layers of foliage, so there is less need to worry about flowering times and interest for each month – the evergreen structure has great stability. Once the foundations are in place and established, designers with an ongoing maintenance remit, more adventurous gardeners can add high-performing annuals and tender perennials that flower for months on end.
This alternative way of using annuals is one of the main distinguishing features this time around. They add the much-needed finesse by punctuating flares of bright colour against a background of dominating deep plum and lush green foliage. These flashes of colour come from flowers like Cleome ‘Senorita Blanca’, Salvia confertiflora and dahlias, which associate well with key structure plants such as Musa sikkimensis, Arundo donax and Tetrapanax papyrifer ‘Rex’.
Spatially, when planting up an urban jungle, it is important to work from the ground up with the aim to cover as many layers with foliage as possible, in much the same way as you would observe in a natural rainforest, with layers such as the emergent layer, the canopy layer, understorey and forest floor.
Amicia zygomeris. Photo: Gary Newell
Top exotic, tender & jungle plants
- Impatiens omeiana is perfect for the forest floor layer. This hardy shade-loving stoloniferous plant is a superb subject for ground coverage, reaching 20cm high and 90cm wide in time. Unlike many plants put forward for groundcover, this is well behaved (not rampant). The dark-green velvety palmate foliage with striking silver veining delivers some much-needed drama to the lower level.
- On the other hand, Indocalamus tessellatus is a bamboo that will run – given space it will cover many square meters. However with appropriate ground preparation, it is a manageable attractive subtropical groundcover species. Despite being a dwarf variety, it carries the largest leaves of any cold-hardy bamboo – foliage is known to reach up to 60cm in length and 10cm in width despite the plant itself only reaching 90cm. Superb for growing in the shadows of large towering canopies, it always delivers on the tropical feeling.
- At first glance Agave montana does not seem to stand out, but its appeal is in its tolerance of the British climate. It comes from high up in the cold moist Mexican mountain forests, growing among oaks and pines. This Agave has evolved to withstand moisture better than many of its A. americana cousins, making it by far the best choice for wet British winters.
- Begonias are anathema to most designers, but there are some hidden gems. When I first saw Begonia luxurians, I thought it was perhaps a rare Schefflera, and could hardly believe it when I learned its true identity. This is one plant with supermodel qualities, hailing from Brazil and standing more than 1.8m tall, with the most exotic palmate leaves you will ever encounter in a British garden. Shade and humidity are needed, and it will have to be brought in over winter, but it is worth the hassle.
- Amicia zygomeris is another weird and wonderful plant, a Mexican pea with unusual pinnate foliage and leaflets with indented tips and purple-veined stipules around the stem. It is hardy down to -10°C, reliably coming back from the base every year and potentially reaching up to 2m once established in ideal conditions.
- Another noteworthy Mexican plant is Cuphea caeciliae, a spreading evergreen sub-shrub in warmer regions, yet a frost-tender perennial in the UK. With a little effort this wonderful plant can be kept going quite easily either by striking cuttings or by heavy mulching, much like we treat Mexico’s other great export, the dahlia. C. caeciliae is incredibly vigorous, so it acts as a great filler on the forest floor, with arching branches carrying unusual tubular red to orange flowers that appear to glow against the elliptic, dark-green foliage.
- Persicaria runcinata ‘Purple Fantasy’ has some of the best markings I have ever seen on any foliage. The lyrate leaves will stop anyone in their tracks with chevrons of green, brown, purple and brilliant silver. When grown in the shade, these markings intensify. It can spread if grown in moist shade, but in most situations the clump forms to around 1m. It also makes a fantastic subject for a shady container.
- Another interesting pot filler is Plectranthus ciliatus, a herbaceous perennial and evergreen in its native South Africa, with prolific pale blue to white blooms and attractive, ribbed, dark greenand- purple reverse foliage. Grown in the UK, it is a vigorous tender perennial, that when grown in the correct conditions can rapidly become a large dramatic subject for container gardening.
- Cestrum ‘Newellii’ is a sub-shrub with arching stems clothed in jewel-like ruby flowers for months on end. Rarely seen growing in British gardens due to its perceived frost tenderness, it is actually hardy to -5°C. It doesn’t need much care or protection when grown in a frost-free urban setting, where it will quickly mature into a 3m-high evergreen with floral interest well into autumn. It can also be wall trained.