Toringo crabapple bonsai

Placement

Toringo crabapple is grown outdoors year-round. Give it full sun: direct light is what produces generous bloom and good fruit set. It does, however, dislike intense heat. Avoid spots in front of a wall or patio that soaks up the day’s heat, and choose a place that is sunny but has good air movement.

The species is very cold hardy in the ground, but a potted tree’s roots are far more exposed to freezing: protect it from hard frosts. Wait for the first frost before sheltering it, because it needs cold to go dormant. Where temperatures often fall below 14 °F, overwinter it in a cold frame or an unheated greenhouse; open them on sunny days so the tree does not wake too early. In a milder climate, simply set the pot on the ground, out of the wind, and wrap it in insulation if you like. Never bring it into a heated room. In spring, its buds and young shoots are very vulnerable to late frosts.

Soil mix

Choose a mix that holds water yet drains well. A deciduous blend works: about half akadama, a quarter pumice and a quarter lava rock. Sift the akadama and lava rock to remove dust, which would clog the pot. If you cannot check the tree every day in summer, raise the share of akadama; in a rainy climate, add more lava rock. Apples dislike acidic soil and water, so there is no need for an acidic mix.

Watering

This is the key point. Throughout the growing season, water thoroughly and never let the root ball dry out, especially during bloom and fruit set: a lack of water makes flowers and young apples drop. Push a finger about 0 in into the soil: if it feels slightly dry, soak the whole root ball until water runs from the drainage holes, then repeat a few minutes later. How often depends on heat, wind, pot size and fruit load: observe rather than follow a routine. In winter, just keep the soil slightly moist. Tap water is usually fine.

Feeding: during the growing season, a solid organic fertilizer every four weeks or a balanced liquid fertilizer every week, applied only to soil that is already moist. Avoid very nitrogen-rich fertilizers during bloom and fruit set: they push the tree toward leaves instead of fruit.

Pruning

The main pruning takes place in late fall, after leaf drop. The buds are easy to see then, and flower buds are easy to tell from leaf buds. You can thin the branches without removing every flower bud, and with them all of next spring’s blossoms. Structural pruning, which removes thick branches, is done in the same season or in early spring; use a concave cutter and cover large wounds with cut paste.

During the growing season, cut overly long or thick new shoots back to one or two leaves, pruning the top and outer canopy harder, since they are naturally more vigorous, so the interior does not weaken. If the tree sets a lot of fruit, keep just one apple per cluster: a heavy crop wears it out. Bloom is often heavier every other year, which is normal for this species.

Canker is common on apples: cut away affected parts, carefully seal the wounds and disinfect your tools between trees. A copper fungicide can be used as prevention.

Wiring

Only young branches and twigs should be wired: older branches become brittle and split when bent. For those, use guy wires, thin wires about 0 in thick anchored to a sturdy root, a strong branch or the pot, with a piece of rubber protecting the bark where the wire touches.

Wiring is easiest in late winter, when the tree is bare. Use aluminum wire about a third as thick as the branch, wrapped at about 45°, from the base toward the tip. Check often during the growing season: wire can bite into the bark within one to four months. Remove it by cutting at each turn, never by unwinding.

Repotting

Repot in spring, as the buds begin to swell: every year for a young tree, every two or three years for an older one. Prune the roots at that time, especially if the tree is weakening, removing no more than about a third of the root mass. Choose a pot slightly larger than usual: it dries more slowly, which helps the tree through bloom and fruit set. After repotting, keep conditions stable and avoid heavy pruning or feeding too soon.

This crabapple can be propagated from seed, cuttings or air layers. Its naturally dense, spreading habit, often with several trunks, and its crown that widens with age lend themselves to a broad, low silhouette.

As for pests, remove aphids, scale, mealybugs and caterpillars by hand or treat them with a suitable insecticide; spider mites call for a miticide, and powdery mildew and rust for a specific fungicide. Finally, the leaves, stems and seeds are toxic to pets: pick up fallen fruit.