Fertilizing
Feed every 1–2 weeks from spring to autumn with a balanced liquid fertilizer, always applied to moist soil to prevent root burn. In winter, feed once a month, because indoor trees keep growing slowly.
Avoid high-nitrogen fertilizer, which produces long internodes and oversized leaves. Do not feed for about four weeks after repotting.
Placement
Give the umbrella tree bright light without harsh direct midday sun, ideally near the sunniest window behind a sheer curtain. It survives lower light, but more light gives more compact growth and smaller leaves.
- Keep it at 18–24°C (64–75°F) and never below 10°C (50°F).
- In summer it can go outdoors in bright shade once nights stay above 15°C (59°F); bring it back in before they cool.
- Raise humidity with a humidity tray, and keep it away from cold drafts and hot radiators.
Pruning
Prune in spring and early summer, when the tree heals and buds back quickly. Cut back long shoots to the leaves you want to keep; a new shoot will grow from the bud above the leaf just below the cut.
- On healthy, established trees, you can defoliate completely in early summer, together with trimming the branch tips, to encourage ramification and smaller leaves.
- Remove oversized leaves at any time during the growing season.
- Encourage aerial roots by keeping humidity high, and guide them down to the soil, where they thicken.
The wood is soft and snaps easily, so shape the tree mainly by pruning. If you wire, use thin wire, bend gently and remove it before it bites in.
Repotting
Repot every 2 years in spring using a standard, well-draining bonsai mix. Handle the fleshy roots carefully, as they break easily, and remove circling or tangled roots while keeping enough root mass to support the tree.
If the tree is weak or stressed, delay repotting until it has regained strength.
Watering
Water thoroughly when the top of the soil starts to dry, keeping it evenly moist but never waterlogged. Good drainage is essential, because standing water rots the roots.
In winter, water less often, but check more frequently if the tree stands near a heater, which dries the root ball quickly. A watering can with a fine rose wets the soil evenly without washing it away.
Seasonal care
- Spring: Repot every two years and start pruning as growth speeds up. Increase feeding to every 1–2 weeks.
- Summer: Move the tree outdoors into bright shade if nights stay above 15°C (59°F), or keep it in a bright indoor spot. Defoliate healthy trees in early summer and water regularly.
- Autumn: Bring the tree back indoors before nights fall below 15°C (59°F). Reduce watering as growth slows.
- Winter: Keep it bright and above 10°C (50°F), away from cold drafts and radiators. Feed once a month and raise humidity.
Common problems
Umbrella tree bonsai are very forgiving, and most problems come from cold, drafts or dry indoor air. The leaves are toxic to cats and dogs if chewed, so keep the tree out of their reach.
- Leaf drop: Usually cold, drafts, a sudden move, or overwatering. Keep it warm and stable, and let the surface dry slightly between waterings.
- Spider mites: Speckled, dull leaves with fine webs in warm, dry rooms. Rinse the foliage, raise humidity and use a miticide on heavy infestations.
- Scale and mealybugs: Brown bumps or white cottony spots on stems and leaf undersides, with sticky honeydew. Wipe them off and treat with insecticidal soap or horticultural oil.
- Long shoots with big leaves: Too little light or too much nitrogen. Move it to a brighter spot, feed less nitrogen and prune back.
- Root rot: Black, mushy roots and wilting despite wet soil. Repot into a free-draining mix, remove rotten roots and water less.