Underplanting and Accent Plants
Ground Cover and Accompaniment Plants for Bonsai
When exhibiting Bonsai formally, they are kept uncluttered. A minimal underplanting of well chosen and perfectly grown moss is traditional. Many judges prefer this to only cover a small portion of the pot’s surface. A well chosen accent plant, in a small separate pot, is better for showing than dense undergrowth. Accent plants also allow the designer to build on the theme started by the tree.
If you are growing purely for your own pleasure, a little more freedom is allowable. Choosing an underplanting scheme can add greatly to the charm of a composition.
How do you maintain the theme of your bonsai with appropriate plants? A root over rock windswept tree, emulates the struggle for life at the tree line, high in the mountains. This or any other “high in the mountains” styled tree would therefore provide a natural home for some carefully chosen miniature alpine plants. There is a bewildering variety of these at many garden centres. Some are termed “choice” – often meaning more difficult to grow. Others grow too large to be in scale with bonsai. So get some advice and ask for the slower growers that remain small. Most alpines appreciate all the light they can get and resent being kept wet in winter. They usually thrive when they are provided with perfect drainage, so there should be no problem in your bonsai soil. Most mountain plants are adapted to growing in small cracks in the rock with hardly any goodness in what little soil there is. The feeding that suits your trees may prove rich for the alpines and they would respond by growing more luxuriantly than in their natural habitat. Taking care to feed the tree only at the roots in the pot, will help. Keep fertiliser pellets away from alpines. Leaves from trees should not be allowed to lie on the alpine plants after autumn leaf fall.
Many alpines are also suitable for planting in dishes with other styles of tree, so long as their light requirements are satisfied and they are not dripped on, whenever the tree receives water.
As well as providing a good variety of foliage types, most alpines can be relied upon to flower every spring before the tree bursts into life.
Many of the plants used as underplantings can be used also as accent plants. Beware though that this does not always work the other way around. Some of the weeds (yes weeds!) that make excellent accents are not at all suitable alongside a tree. This is because they will romp around in the pot and rob the tree of nutrients. Eradication can then prove difficult with some of the more persistent ones. Even a total soil renewal can often leave seeds that begin the process of infestation once again.
A few Suitable Alpines
- Arenaria balearicais a tiny creeping plant that forms a bright green mossy cover with tiny white starry flowers in spring. It is suited to a moist, shady site.
- Calluna vulgarisHEATHER dwarfer forms may be kept clipped for compactness
- Frankenia thymifoliaSEA HEATH The wiry creeping stems of this small plant have grey downy leaves and very small rose pink flowers in summer.
- PotentillaDWARF POTENTILLA Several of the dwarf species are suitable and have flowers in shades of yellow.
- Pratia angulatais a mat forming, perennial, alpine plant. Slender stems and a small pale green leaves. Stemless, white flowers.
- Raoulia australisis a minute, mat forming, blue-grey plant with unobtrusive, stemless yellowish flowers in July. Its leaves and flowers are so small it looks almost like a blue moss.
- Saxifragais a huge genus. Choose the smallest encrusted varieties which form charming hummocks of tiny rosettes. They have spikes of small, generally white flowers in spring. The Mossy and Kabschia groups of saxifrages also have suitable candidates. Saxifraga oppositifoliaand its varieties have flowers in purple shades.
Apart from the Alpines, some other small forms of plants are equally suited to life in a bonsai pot. Success is, as always, dependant upon understanding the needs of the plant and matching it to the tree.
Dwarf grasses & Rushes
Short grasses can be used for accent plants or even beneath trees as long as they appear in scale. Some thinning and the occasional “haircut” with scissors may be beneficial.
- Festuca glauca- Dwarf Sweet Rush is a good bluish grass that will suit larger trees.
- Juncus effusus spiralis- Spiral Rush a dwarf rush with spiral stems like corkscrews. An acid soil mix kept permanently moist suits these, so only plant with trees that demand constant wet – Alder, Willow, Swamp Cypress etc.
- Equisetum hiemale- Dwarf Horsetail (Scouring Rush or Equisetum) Not really a rush, but one of the primitive horsetail ferns. This again is one for damp plantings only. Roots tend to be invasive so be certain that you want this in your bonsai pot before planting, if happy it may prove difficult to eradicate!
A large sized, woodland tree shaped bonsai or any large forest planting would be an appropriate place for some of the smallest fern varieties. Try to get hold of ferns such as Athyrium filix-femina crispumthe DWARF LADY FERN.
These slow growing, colourful patches of unusual plant are a symbiosis between fungi and algae. They are very choosy as to what they will grow upon and where. Some adhere to bark in damp shady areas others only on fully exposed and well drained rocks. The rock type, air and water quality all help determine whether or not they will survive. The easiest way to include some is to use a lichen covered rock from near where you live, paying attention the microclimate it enjoys and place it on the soil. Alternatively detach a small piece of lichen and wedge it into a tiny crevice. If you are lucky it will take hold and spread, but will grow very slowly. I have tried painting my newly made Japanese lantern with yoghurt and cow muck in an effort to encourage lichen growth but all this has achieved (so far) is instant ageing of the surface.
Choose the drought resistant, short growing varieties. Suitable pieces from slate roofs, on paving slabs, walls and rocks can be dried and crumbled onto the soil surface. Keep shaded and dampened by mist spraying until the mosses are established.
All of these are happiest in well drained conditions. Sedums, such as stonecrop, tend to be a little on the invasive side but are easily curbed as the stems remain on the surface of the soil and root shallowly. Sempervivums- also known as houseleeks, are hardy, rosette forming succulents. Some grow too large but there are many smaller forms to be found. Sempervivum arachnoideumis my favourite as it remains small and becomes reddish with a fine covering of cobweb like hairs in well drained conditions. Sempervivella alba- a Himalayan plant consisting of many small hairy rosettes with a loose mat forming habit and fleshy, white, daisy-like flowers.
Dwarf varieties of Thyme form a carpet of tiny deep green leaves and are smothered with tiny purple flowers in spring.
Some Details On Accent Plants
The care of all accent plants is comparable to that of mame trees. Watering correctly is the skill that must be mastered before healthy growth will be achieved. In small pots drying out is the greatest obstacle. I find that standing the pots in a tray of peat, sharp sand or vermiculite that is kept constantly damp (not soggy) is the best way to overcome this. Some overhead protection through the winter is advantageous, especially for the alpines that dislike winter wet. Many are used to being insulated under a layer of deep dry snow in nature.
I have only given details of a few of the suitable plants here. Dedicated accent plant enthusiasts are constantly seeking new and interesting subjects to display alongside their trees. By vigilant observation of all plants you can come across unusual and evocative accent plants. Trying anything that you think may be suitable often leads to surprisingly good results. A single Dandelion, in a miniscule pot, becomes elevated far above the commonly detested weed of our gardens.
Surprisingly, the choice of a pot for an accent plant can be just as much of a challenge as that for a prized bonsai specimen. Small pots as used for mame or shohin trees are becoming more readily available. Companies such as Walsall Ceramics Studios now have an excellent range. If you have the time, it pays to look long and hard to find the ones with the best glazes.
A word on availability. Many of the varieties above may be difficult to find in garden centres. Try specialist retailers and bonsai nurseries. If you cannot locate any plant, then the Royal Horticultural Society’s Plant Finder is an excellent source of information with listings of over seventy thousand plants and details of which nurseries stock them. (Incidentally this is an essential to have in the car when travelling. There are a great many specialist nurseries for trees, shrubs, bamboos etc tucked away in obscure areas, many of them with gems well worth seeking out.)
Remember to achieve harmonious groupings, be adventurous in your choices but always keep natural associations in mind. The palette is nature herself, the paintbrush your imagination and the canvas your finished display.