Bonsai trees are miniature trees that are cultivated in containers and carefully pruned to control their growth. Over 250 species of trees exist that can be grown as bonsai, and all of them began with a seed. Reproducing bonsai trees from seeds requires knowledge of the specific germination process and optimum soil type of the tree species you are growing. Two primary ways exist to germinate seeds; natural and forced. The natural way is to plant them in the proper soil during the fall and by spring they will sprout. Forced germination requires scarification, or softening the shell, so that water can reach the center of the seed. The scarification process may include placing the seeds in a bowl of water or boiling them, depending on the species. Some tree species need cool weather to prepare for germination. This process is called cold stratification which you can duplicate by wrapping the softened seeds in a paper towel and storing them in the fridge until they germinate. Other species need a bit of warmth during the cold stratification process and others can go straight into the soil after the scarification. Before you try to reproduce a bonsai tree from seeds, make sure that you are aware of the correct germination process for the tree species.
One of the most common ways to reproduce bonsai trees is to take a cutting from the parent plant and root it to propagate a new tree. Typically, your bonsai tree will reproduce faster from cuttings than if you started one from seeds. Take your cutting from a healthy bonsai tree of any variety. Cuttings should be between 2 and 4 inches long, with four to five knots within that length. Knots are where leaves connect to the stem. Make your cuttings 1/4 inch below a knot with a sharp knife. The angle of your cut is also important when you are propagating bonsai trees or any plant species; clean cuts at a 30 degree angle work best. Before attempting to root your bonsai tree, remove the bottom leaves and any sprouts that may be growing from the cutting. You should be prepared to plant the cuttings right away, while the stem is fresh. Rooting stimulators aid in root development and are simple to apply, dip the clean end of your cutting briefly and shake off the excess before planting. Plant the cutting into a small pot with a 50-50 mixture of water soaked peat and sand, or perlite and peat to wait for the roots to develop. Maintaining high moisture content is beneficial for root development; consider covering the cutting with a plastic bag for most of the day to create a humid atmosphere. Planted cuttings need indirect sunlight for most of the day to produce roots.
Grafting is another way to reproduce bonsai trees. Grafting a bonsai tree is the process of placing a section of one tree into a slice of another. You can use many different grafting methods to reproduce bonsai trees, depending on the species you are working with. These include the splice graft, whip and tongue graft, saddle graft, cleft graft, veneer and side graft and bare root grafting. The tree species must be compatible for the grafting process to be successful.