How to Cultivate and Care for Bonsai Trees
Learn these botanical basics to fully succeed at planting and caring for your bonsai tree.
Bonsai is said to be an art form, but you still need to know some basics on caring for bonsai tees to be successful.
"The first thing to know about bonsai is that it isn’t a type of tree. That’s a pretty common misconception," says Justin Hancock, garden expert at Costa Farms. "Bonsai is a way of growing a tree — a specially pruned tree grown in miniature. Regular pruning of the roots and top growth helps keep the plant the size you like, no matter how old the tree or shrub gets."
The Chinese created the first miniature landscapes, a practice that Japanese growers modified when they began focusing on individual trees. "Bonsai became part of the ritual for some Buddhist monks before Westerners were exposed to the art of growing mini trees and bonsai went mainstream," Justin says.
The art of bonsai is more than 1,000 years old. Explore the trees, shrubs, perennials and vines you can use to create your own sublime miniatures.
Justin has seen oak, pine magnolia and even citrus trees pruned in the ancient bonsai tradition. "Ficus Ginseng and Fukien Tea are especially popular, but you’ll also find Japanese maples, ginkgo and junipers," he says. "Virtually any tree or shrub can be grown in bonsai form."
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.
Bonsai expert Dolly Fassio 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."
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 Dolly.
Picking Your Bonsai Planter
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. There are so many pretty pots to choose from, but Justin suggests the perfect bonsai planter is the one that’s "about as deep as the width of the trunk and about as wide as the tree’s canopy."
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.
Justin says that if you create your own mix, be sure it holds enough moisture that you don’t need to constantly water your bonsai. He says the soil needs to allow for excellent drainage so the roots don’t rot in their confined space and should be loose so the roots get enough oxygen.
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, so repotting is necessary. 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.
Bonsai in Balance
The key to bonsai is keeping the amount of top growth and root growth in balance. "Too much top growth can’t be supported by the roots, and the tree ultimately fails," Justin says.
Check the Label
Justin says watering requirements, pruning times, indoor vs. outdoor placement and light exposure depend on the type of tree. "The key is pruning and remembering to treat it like the kind of species it is," he says.
Growing bonsai isn't just an art — it's also a science. Learn more about how to grow a healthy bonsai tree, and what might be wrong if yours is looking a bit sickly.
The Best (and Easiest) Bonsai
There are a few indoor and outdoor species that are more reliable and easier to care for, especially for bonsai beginners. Popular indoor choices include:
Ficus. This is one of the most popular bonsai species because it’s easy to maintain and will be tolerant of mistakes as long as you give it good light, proper drainage, and regular feeding.
Schefflera. This plant won’t readily succumb to mistreatment, so it’s also good for beginners. Like all bonsai, it needs regular watering, good drainage and regular pruning.
Fukien tea. This tree (also known as Carmona), needs a lot of light, so you may have to provide supplemental lighting. It also needs humidity, and a tray of wet stones underneath the container may satisfy that need.
Dwarf jade. Already an easy-to-grow houseplant, jade trained as bonsai grows as a woody shrub with succulent leaves that can go slightly longer between waterings. Frequent pruning allows it to grow stronger; it’s also easy to propagate from cuttings.
Outdoor bonsai should be chosen with your particular climate in mind. Popular outdoor species:
Juniper thrives in bright sunlight. Protect the tree during winter where the temperature drops into the teens, but it must remain outdoors. Allow the soil to become slightly dry.
Japanese maple does best in a sunny location with light shade during the middle of the day. It may need to be watered daily during the growing season – even several times a day on extremely warm days.
Azalea likes shade from hot mid-day sun. Azalea bonsai will bloom in season; flowers will last longer if the bonsai is protected from hot sun and heavy rain. Water regularly, but not so much that the roots are soaked.
Pine grows best in full sun. These evergreens are hardy, even in their shallow containers, but should have some protection outdoors during winter. Provide good drainage, and protect the trees from too much rain.