Bonsai is the Japanese art of training trees and other plants to grow in miniature. The effect is accomplished by growing the plant in a small container, but otherwise, the plant is normal. Bonsai seeds are no different from the seeds of regular plants; bonsai trees are not genetically dwarfs, but rather trained to grow small as an art form.
There are two methods for growing a bonsai plant: using cuttings or bonsai seeds. Beginners may wish to forgo either of these methods and start with a stock tree; they will still have control over the eventual shape and design of the tree, and can practice bonsai without having to wait for a plant to grow. However, growing a bonsai tree from scratch gives one the most control and can be very gratifying.
Bonsai seeds are the most challenging approach to bonsai and take a longer time to grow into a plant than cuttings, but they also provide the best control over the entire process. Bonsai seeds can come from trees found in the park or the woods or one's own garden, or they can be obtained through a supplier. If you wish to collect your own seeds, autumn is the best time to do so. Buying bonsai seeds from a supplier, however, has many advantages: the risk of fungal or viral disease is mush lower, you will know exactly what kind of plant you are getting, and you will know that the seeds are suited to bonsai.
Most tree seeds have a tough outer shell and should be soaked in lukewarm water for 24 hours prior to planting. The protective coating must be broken open to allow the seed to germinate, either with pliers or by making an incision. Be careful not to damage the seed when breaking its shell.
Some combination of peat, loam, and sand is best for bonsai seeds, depending upon the specific type of seed. Whatever type of soil is used, make sure that it is moist and free of impurities by passing it through a coarse sieve and disinfecting it with steam or a formalin-based product. Stratification, in which bonsai seeds are layered in a container with moist sand, is necessary for many types of seeds to grow. In order to prevent fungal and viral infections, you may soak the seeds in a disinfectant prior to planting and apply fungicide shortly after germination.
When planting bonsai seeds, cover the bottom of the container with a layer of sand or fine gravel to ensure effective drainage. Plant seeds on top of 3/4 inch (2 cm) of soil, making sure to give them enough room so that they will not crowd each other as they grow. Cover them with another thin layer of soil. The seeds must be able to breathe, so the smaller the seed, the less soil it should be covered with. Immediately after covering the bonsai seeds, lightly tamp down the soil and give them their first gentle watering, using a fine spray.
Bonsai is a delicate process from first planting the seeds. Make sure they are in the shade and safe from frost at 60-70°F (15-20°C). Covering the container with glass, leaving a corner open to allow air circulation, can help maintain the proper temperature and prevent evaporation. Above all, be patient, as bonsai seeds can take up to a year to sprout.