How to Cultivate and Care for Bonsai Trees
Bonsai is said to be an art form, but you still have to have some botanical basics to be successful. Bonsai is essentially a tree in a tiny tray; you can even train other types of plants.
Pruning, bending, tying and repotting all help keep the tree compact. Interestingly, if you were to take a bonsai tree and plant it in the landscape, it would grow into a regular-sized tree again. That, of course, defeats the purpose of the art but points out an important aspect. Bonsai are not houseplants. "They grow in nature outdoors, so you really need to keep them in their natural environment," says bonsai expert Dolly Fassio.
Many kinds of plants can be trained to be bonsai. Dolly suggests beginning with a one-gallon, container-grown plant purchased from a reputable nursery, preferably one that specializes in bonsai. "You need to get a tree that's easy to take care of in your area so you know that it will live in your environment."
There are five basic bonsai styles:
- The formal upright style highlights a straight trunk
- The informal upright style is curved and moving
- A slanted trunk flows gracefully to one side, and a variation of this style is called "windswept" for obvious reasons
- A half- or semi-cascade drapes over the pot
- A full cascade drapes beyond the pot's rim.
The tree itself will often dictate the bonsai style. But don't forget its container. The bonsai pot should blend with the tree and add value and interest. Containers vary in size and price.
Bonsai Azalea in Bloom
"Most azaleas used in bonsai are Satsuki azaleas," says Barbara Bogan, Executive Secretary of the American Bonsai Society. These plants (Rhododendron indicum) have evergreen leaves and summer flowers. "(This) is an exposed root azalea." From the collection of Dave and Barbara Bogan of Indiana.
Shimpaku Juniper Bonsai
Because of its hard, resinous wood, Juniperus chinensis 'Shimpaku' is a good choice for sculpting into advanced forms. These Japanese natives are best grown outdoors, so they're exposed to the natural change of the seasons. Eric Schrader, president of the Bonsai Society of San Francisco, says "All bonsai need to be protected from temperatures below 28 degrees, and from freezing winds. Winter protection should take the form of a cold frame for most species, or a space heated to between 32-36 degrees for the duration of the winter."
Japanese White Pine
Nicknamed Bertha, this bonsai is a Japanese white pine, believed to be over 100 years old. It was imported from Japan from the late Daizo Iwasaki's nursery," says bonsai expert Barbara Bogan. (Iwasaki was a renowned bonsai collector.) From the collection of Dave and Barbara Bogan in Indiana.
Literati Bonsai Style
Photographed in the spring, these three Japanese black pines were trained in the literati style. Literati is a Latin word indicating refinement and elegance; the style doesn't have specific rules, but typically involves twisted trunks and few, relatively sparse branches. "Literati style is also known as bunjin," says Schrader, named for "the cultural elite in Japan and China...They developed a sparse and elegant style in bonsai that was different than the traditional, powerful image. Think of a bunjin tree like a fine whiskey - it should have a strong character that is subtle, and typically it is not well-appreciated by those who have not developed a taste for it."
Japanese Black Pine Bonsai
These seedling Japanese Black pines sparkle when they catch drops of morning dew. "One of the most popular species for bonsai, Japanese Black pine grows vigorously in many climates," says Schrader. "Growing from seed is the best way to create a high-quality tree and can take as little as 10 years."
The foundation to bonsai is the soil. Bonsai trees need a special soil because they're confined to small pots. Use volcanic mixes containing pumice, fir bark and lava rock for a well-draining soil. The roots hit the sharp edges of the pumice and form more hairlike roots. Fine hairlike roots are better for the tree's health than large roots, says bonsai enthusiast Fred Fassio.
All bonsai need to be repotted periodically. Eventually the roots will grow in and fill the pot. At this point the tree is root-bound and can't absorb enough moisture. Repotting is an art form itself, and this Asian skill calls for Asian tools. Upon pulling the plant out of its pot, Fred uses a chopstick to separate the roots. It's best to repot during the tree's dormancy period since cutting the roots actually encourages new growth. Cut off approximately one-third of the roots from the bottom and around all the sides of the rootball.
In nature, a taproot anchors the tree in the ground. With bonsai, wire does the trick. Thread wire through small holes in the pot. Next, add some soil around the rootball and gently twist the tree downward into the soil to get as much of it into the tree's roots as possible. Tighten the wire over the tree's larger roots, clip away the wire, and tighten it again securely. If the roots are properly wired in the pot, you should be able to pick the tree up by the trunk, and it won't come out of its pot.
Add a few more scoops of soil over the roots and use a chopstick to push the soil down into the tree's roots. This eliminates air pockets that can damage or even kill the tree. The finishing touch is a layer of pre-moistened moss; this helps to add beauty and maintain moisture.