Autumn colour, Oriental-style
The trend towards tinier gardens means that often there’s not room for large trees and shrubs. But that doesn’t mean that you can’t have autumn colour, because fortunately small specimens are a possibility. Elegantly-shaped Japanese maples fit the bill, easily slotting into most gardens, which is good news for those wanting an Oriental touch to their water garden or Koi pond, without going over the top.
These plants’ small size, slow growth, delicate foliage and glorious autumn colours make them ideal specimens for the garden. It’s best not to overdo it in a small area – choose two or three at the most in complementary colours. Being expensive plants, you probably won’t want to buy too many in any case. The reason for their higher price is the fact that many are grafted, which is a longer process than growing seedlings, and these slow-growing plants take some time to reach a saleable size.
All Japanese maples are deciduous, but the result of them dropping their leaves is to reveal the delicacy of their skeleton of branches that create a rounded or spreading outline. And although most have dull bark, a coating of frost adds to their beauty. For a winter-long display of glowing colour, there are maples with colourful young stems such as the widely available Acer palmatum ‘Sango-kaku’ (often sold as ‘Senkaki’) or coral-bark maple, with coral-red growth, and the harder to find ‘Corallinum’ with pink stems and young leaves. Also look for all year show stopper A. palmatum ‘Bihou’ or ‘Bi-ho’ from Gardening Express and Thompson and Morgan.
Growing needs of Japanese maples
Where to plant?
Before deciding which maple to buy, it’s worth considering its planting position. These plants have delicate foliage that is easily damaged by strong winds. The leaves can turn black with wind-scorch and frost, with the just-unfurled leaves being particularly vulnerable, so it’s essential that you provide a site sheltered from cold winds. It’s more difficult to find a frost-free spot, but there’s always the insurance of a length of lightweight fleecy mulching fabric (from Gardening Direct or Thompson and Morgan) which can be draped over the plant as temporary protection during critical times.
A sunny place, whether for the whole or part of the day, is also important for Acer japonicum to grow well, except for yellow-leaved forms (such as ‘Aureum’) that scorch in full sun. These are more suited to shady sites. If you are restricted to shady spots, you could also choose Acer palmatum or one of its cultivars (from Gardening Express and Thompson and Morgan) as they will tolerate these conditions.
Guaranteed autumn colour?
Most Japanese maples (from Gardening Express and Thompson and Morgan) give a reliable autumn display but to make sure of this, choose your type carefully. Those with red or purple leaves may turn to scarlet, but others don’t change at all. Neither will some of the yellow-leaved types.
It’s the bright green leaves which dependably provide the show, turning to rich crimson, orange or yellow in autumn. The display is improved if you can grow the plant in a neutral or acidic soil, so if you garden on chalk or alkaline clay, add lots of garden compost, potting compost or leaf mould to the soil.
Alternatively provide ideal soil conditions by growing these maples in large tubs of compost. Use tubs or buckets with drainage holes, and bury them up to their rims so that the shrubs appear to be growing in the soil, or place the maples in glazed pots to add to the Oriental effect.
Whichever you do, don’t forget to water the plants well in dry spells, evem those plunged to their rims, but make sure that the roots cannot become waterlogged. Or for above ground pots, choose self-watering containers.
Positioning Japanese maples for effect
It’s important to consider the background when planting Japanese maples. A uniform backcloth of a dark fence or evergreen hedge will show off the summer and autumn leaf colour to perfection and is essential in winter to appreciate bright stems.
With their graceful low branches, these shrubs are ideal for positioning at the edge of the pool where they can cast a little shade for Koi and other fish, and create a reflection on the still water.
Types of Japanese maple
The common name of Japanese maple is given to two different species – Acer japonicum and Acer palmatum. A. japonicum grows slowly into a bushy tree with a single trunk or a shrub with multiple stems, reaching 5-10ft after ten years. A. palmatum is of similar stature, usually growing on one stem as a small tree, although its low and mounding growth gives it a shrubby appearance.
Both have beautiful foliage with typically lobed leaves. A. japonicum and its cultivars have 7-13 lobes per leaf, each growing to 3 – 5 1/2 inches long on downy stalks. A. palmatum has 5-7 lobes per 2 – 4in leaf, and there are so many variations that horticulturists have divided the species into three groups. There are cultivars with 5-lobed leaves, those with larger (up to 5in) 7-lobed leaves and those having finely divided thread-like 7-11 lobed leaves. It’s the finely divided leaves that have led these to be named as the dissectum group. This is the group that includes those much-admired shrubs giving a sculpted effect due to their drooping branches.
Apart from dissectum cultivars (from Gardening Express and Thompson and Morgan), another name to look out for is ‘Osakasuzi’, which is one of the 5-lobed leaf group. This cultivar is widely available and rightly so, because its yellowy-green leaves reliably turn to brilliant blood-red in autumn. Try Gardening Express and Thompson and Morgan.
However, don’t make the mistake of setting your heart on one particular maple too quickly – instead take the opportunity to visit a few gardens and note down names. Even better, try and see the national collection of Japanese cultivars at Westonbirt Arboretum in Gloucestershire to compare their shapes, sizes and colours.
Having decided which maples will suit your garden, you may have difficulty finding them for sale, although many are widely available. The simplest way to track them down is to phone around your local garden centres (listed in the Yellow Pages). If none of these stock your choice, then the RHS Plant Finder will guide you to sources of supply.
Where to see Japanese maples
Westonbirt Arboretum, Tetbury, Glos GL8 8QS. Open daily 9am-dusk (check opening times on the website before travelling), admission rates depend on the season, with autumn being the highest priced.
Telephone 01666 880220 to check whether the maples have developed their best autumn colour and visit the events page of their website.