Bonsai Care: a watering, pruning and repotting log for your trees

The useful test is whether it holds a record that spans years, because that is the timescale bonsai actually works on. It also has to cover more than watering — wiring and repotting dates matter most when you are trying to remember them two seasons later — and it should keep photos next to the log. Bonsai Care - Tree Journal is built that way: six separate task types, a per-tree history you can scroll back through, side-by-side growth photos, a calendar across the whole collection, and a 42-species reference guide. Free on iOS and Android.

There is no fixed interval, and following one is the most common way to lose a tree. Bonsai are generally watered by observation: check the soil surface and just below it, and water thoroughly when it is approaching dry, until water runs out of the drainage holes. How often that falls due depends on species, pot size, soil mix, season, indoor or outdoor position and the weather that week. A tropical indoors and an outdoor pine in summer can differ by days. A dated log is useful precisely because it shows your own tree's real pattern.

It depends entirely on the species, and this is where most beginners go wrong. Tropical and subtropical trees — ficus is the usual starting point — can live indoors year round given bright light and reasonable humidity. Temperate species such as juniper, pine, maple and elm are outdoor trees. They need the seasonal cycle, including a cold winter dormancy, and generally decline in a heated room even though they are sold as houseplants. Check what a species needs before you buy it rather than after the needles start browning.

For most species the usual window is late winter to early spring, as buds begin to swell but before strong growth starts, so the tree can recover into its growing season. Frequency varies widely: young or vigorous trees often go every one to two years, mature conifers considerably less often. Common practice is to remove a modest portion of the root mass — many growers work to around a third — and return the tree to fresh substrate. Species, age and climate all shift this, so check guidance for the tree you actually have.

Only until the branch holds its new position on its own. That can be a few weeks on a fast-growing deciduous tree or many months on a slow conifer, so the honest answer is to check the tree regularly rather than trust a date. The risk is the wire biting into bark as the branch thickens, which leaves marks that can take years to grow out or never fully do. Most growers cut wire off in short pieces rather than unwinding it. Recording the date wire went on is what makes the check happen.

Temperate species need their winter dormancy, so the goal is not to keep them warm — it is to protect the roots. In a shallow pot the root ball is far more exposed to freezing than the same species planted in the ground. Depending on the species' hardiness and how cold your winters get, keepers heel pots into the ground, mulch them, or move trees to a cold frame or an unheated shed or garage. Bringing a dormant temperate tree into a heated house is generally the worst option available.

Yes. It is free to download on the App Store and Google Play, and the core journal is free to use: multiple trees, the full care log across six task types, the photo timeline, the calendar view and the species guide. A Pro upgrade adds AI seasonal care plans and species-tuned watering, wiring and repotting reminders. The app is rated 4+ and the current version is 1.6.0.

Yes. Each tree in the collection gets its own record, with its species, age, and full task history stored on that tree's page. The calendar shows upcoming and past care tasks across the whole collection at once, which is the part that matters when several trees are on different watering and pruning schedules. You can also scroll back through months or years of a single tree's log in one place, so the history stays per tree rather than becoming one undifferentiated list.

They generate a plan for one specific tree, covering watering, fertilizing, pruning, wiring and repotting, tailored to that tree's species and the current season, with practical tips attached. It is part of the Pro upgrade. Treat it as general care reference rather than a substitute for hands-on bonsai instruction — for a tree that is struggling, or one that is valuable to you, the right move is to consult an experienced grower who can look at it.

Yes. You set your hemisphere once and every seasonal cue flips accordingly, including pruning windows, dormancy and repotting season. This matters more in bonsai than in most hobbies, because nearly all published care advice is written for a northern calendar — an instruction to repot in March is straightforwardly wrong if your early spring falls in September. Setting it correctly at the start keeps the seasonal guidance aligned with the year you actually experience.