How to Make an Instant Bonsai Tree. Bonsai is the ancient Japanese garden art of training miniature trees. Here's a quick and easy way to create miniatures that have some of the character of true bonsai without the painstaking demands.
Select a tree. Start with common garden plants such as azalea, boxwood, camellia, cotoneaster, gardenia, hibiscus, holly, juniper, pyracantha and rhaphiolepis. Look for 1-gallon-sized shrubs with branches that either grow upward or hang facing down - whichever you prefer.
Using bypass pruners, make an initial pruning of the plant while it's in the original nursery container. Find its central trunk and remove enough growth until you plainly see the structure of the front - the side that will be displayed.
Remove the plant from its container and place the root ball in a bucket of water. This will make it easier to reduce the soil around the roots for fitting into a bonsai container.
Remove as much of the soil around the root ball as possible to fit the plant into a shallow decorative container.
Trim the roots until they are reduced to 2/3 of their original size. You will have a shallow root ball when you are finished pruning.
Place a piece of plastic window screen over the container's drain holes to prevent the soil mix from washing out as you water. The screen will also prevent insects from entering through the holes.
Add a 1-inch layer of potting soil mix to the bottom of the container.
Place the plant in the container, spread the roots out over the layer of soil, and cover them with more soil. Make sure you leave at least 1 inch of space below the rim of the container so you can water.
Finish pruning the remaining foliage. Trim away stems and branches in such a way that the remaining growth has the branch structure of a tree. Keep in mind that once you cut something off, you can't put it back.
Water the tree well to soak the soil thoroughly.
Cover the surface of the soil with aquarium gravel for a finished appearance.
Feed with small amounts of fertilizer at frequent intervals, or choose a slow-release fertilizer. Fish emulsion or cottonseed meal are recommended sources of nutrients.