There are many ground covers that can be used as an alternative to just plain moss. For one, they are a lot more hardy and tolerant of changes in temperature and also more interesting than a simple green covering.

An easy, and very hardy ground cover to use that can be constantly multiplied is 'Helxine/Soleirolia solerirolii' (Baby Tears). A lot of bonsai nurseries use this, providing an instant and bright covering to greatly enhance the plants' appearance. This creeping plant has yellow-green small round leaves and tiny white, pink-tinged flowers, which occur singly in the leaf axils. It has an indefinite spread, and can be invasive if not controlled - but this is no problem in a properly maintained bonsai. It does not crawl up the tree, and if it does hang over the edges of the pot, just pinch the growing tips off. The small flowers are not that prominent, but having the plant is a great asset. The cover is usually expensive if you buy it at the nursery, but if you buy just buy one pot or propagate it of a friend, the plant will multiply quite rapidly after a few weeks.

A good feature plant to be planted sparingly alongside bonsai to give a very realistic effect is 'Kyoto Dwarf' Mondo Grass ('Ophiopogon Japonicus' or 'Liriope Japonica' ). This fine-leafed species is native to Japan and Korea and thus has quite a significant prominence in the world of Japanese bonsai. The short, dark green recurving foliage arises from rhizomes, spreading to form dense, soft mats of at max. 4-5cm high. It is a good cover to use, but should not be allowed to cover more than an sixth of the area of the pot (especially small pots) as this could restrict the bonsai's growth. It should be divided up each time that the bonsai is repotted - every 2-3 years. It is again a very hardy plant and multiplies rapidly from a very small portion. Used frequently in Asian courtyards and formal gardens, it should not be that hard to obtain. (Also used as an accent plant for bonsai.)

An alternative to using a 'live' ground cover is using a very popular medium among bonsai nursery owners called 'iron stones'. These are very small stones (2-4 mm in diameter) not made out of, but in the colour of iron. They are reasonably cheap if bought in bulk. Only a little amount is needed to just cover the area of a bonsai pot. They make the bonsai look very professional indeed, and are an instant solution if you can't be bothered with, or can't get, moss to grow.

Depending on the actual size of your bonsai and bonsai pot, you can also use small bulbs which appear every spring with quite a magnificent show of colour (also used as accent plants) - although you have to be wary that they do not take too much focus off the main tree. Some varieties you could try are 'Ipheion Uniflorum' (Spring Starflower) which have triangular, white, light or dark blue shaped petals; and you can also try 'Rhodohypoxis Baueri/Baurii' (Rose Grass) which is a small tufting shrub with short, grass-like foliage and colourful pink, red or white flowers during spring and early summer. This plant is quite well known and you might be able to find it in pots at nurseries when it is in season - or order it from a bulb mail order catalogue.

Although these plants work quite well in bonsai as either ground covers or plants to complement the main tree - be careful by routine pruning and repotting that they do not take over the pot.