How to Take Care of a Bonsai Tree: Light, Water, Pruning

Q: How to take care of a bonsai tree

Know whether your bonsai is an indoor or outdoor species, give it plenty of light, water when the top of the soil just starts to feel dry (often daily in summer), and trim new growth to keep its shape. Repot every 2 to 5 years.

That’s good news, because it means bonsai follow the same rules as any other tree, just on a tighter budget of soil and water.

Indoor or outdoor bonsai?

This is the most important question, and getting it wrong is the top reason bonsai die.

Type	Examples	Where it lives
Outdoor	Juniper, pine, Japanese maple, elm	Outside all year; most need a cold winter rest
Indoor	Ficus, jade, Fukien tea, Hawaiian umbrella	Inside on a bright windowsill, outdoors in warm summers

The juniper often sold in shops as an “indoor bonsai” is actually an outdoor tree and slowly declines inside.

Watering

Bonsai pots hold little soil, so they dry out fast. Check every day: when the top layer of soil just starts to feel dry, water thoroughly until it drains from the bottom holes. Never let the soil dry out completely, and don’t water on a fixed schedule; in hot weather that might be daily, in winter every few days.

Light and placement

Indoor bonsai need the brightest spot you have, close to a window. Keep them away from heaters and air conditioners, which dry out leaves. Outdoor bonsai do best with morning sun and some afternoon shade in hot climates.

Pruning and shaping

Pinch or trim new shoots back to one or two leaves once they’ve grown a few more, to keep the tree compact.
Wire branches gently to bend them into shape, and remove the wire before it cuts into the bark.
Repot every 2 to 5 years in spring, trimming about a quarter of the roots.

Feeding

Use a balanced liquid fertilizer at half strength every couple of weeks during the growing season, and much less in winter.

Prefer something faster-growing to start with? Kitchen herbs teach the same watering skills with quicker results.