Gadenin日本語Get the appCheck the soil, do not count the days
The single most useful habit with this tree is to check before every watering rather than watering on a fixed day. How fast a bonsai pot dries depends on the season, the room temperature, how much sun the pot gets, how many leaves the tree currently carries, how old the soil is and how big the pot is. Those things change constantly, so any fixed interval is wrong for most of the year.
Push a finger about an inch (2.5 cm) into the soil. If it comes out with damp soil clinging to it, wait. If it comes out dry and clean, water. A wooden skewer pushed to the bottom of the pot and pulled out tells you the same thing about the deep soil, which is where rot starts and where your finger cannot reach. Lifting the pot works too once you have learned what wet and dry feel like on the same tree.
As a rough expectation rather than a rule: indoors in the warm months a small ginseng ficus in bonsai soil often wants water every two to four days, and in winter every seven to twelve days. If your tree is far outside that range, the pot size or the soil is the reason, not the tree.
Water thoroughly, then let it drain
When you do water, water properly. Take the tree to a sink and pour slowly over the whole soil surface until water runs freely from the drainage holes, then pause and repeat once. Dry bonsai soil is water-repellent at first and the first pour mostly runs down the sides, so the second pour is what actually wets the root ball.
Then let it drain completely and never leave the pot standing in a saucer of water. A pot sitting in water has no air in the bottom third of its soil, and roots in airless wet soil die and rot. If you use a decorative outer pot, tip the water out of it after every watering.
Small daily splashes are the worst pattern of all. They keep the top wet, which reads as watered to you, while the bottom of the pot stays dry and the roots there die back. Fewer, complete waterings are always better than frequent partial ones.
| Condition | Roughly how often | What is driving it |
|---|---|---|
| Warm room, full canopy, bright window | Every two to four days | Active growth and high transpiration |
| Outdoors in summer sun and wind | Daily, sometimes twice | Wind and sun strip a shallow pot fast |
| Cool room, short winter days | Every seven to twelve days | Growth has slowed and evaporation is low |
| Tree has just shed most of its leaves | Half the usual frequency | Far less leaf area to lose water through |
| Recently repotted into fresh soil | Just moist, never soaked | Cut roots cannot drink and rot easily |
| Old, broken-down soil | Appears to need less, actually drains badly | Repot rather than trying to water around it |
Room-temperature water. Cold water straight from the tap on a warm-growing tropical tree causes a check to growth and, on an already stressed tree, a round of leaf drop.
Telling too much from too little
This is where most ginseng ficus are lost, because the two problems look alike. Both give you yellowing leaves that fall. The instinctive reading of yellow leaves is that the plant is thirsty, so people water more, and if the real problem was wet roots that finishes the tree.
The soil settles it. Yellow leaves plus soil that is still damp several days after watering is overwatering, and the fallen leaves are often soft and blotchy rather than crisp. Yellow or crisp leaves plus soil that is bone dry, with the pot feeling light and the leaves limp before they fall, is underwatering. If the soil is wet and the leaves are yellowing, the correct action is to stop watering entirely until the top inch (2.5 cm) has dried out, not to water more.
A tree that has dried out badly recovers surprisingly well: soak the pot in a basin of water until bubbling stops, drain it, and expect to lose some leaves. A tree that has been kept wet for weeks may have lost its fine roots already, and recovery means getting it out of that soil, cutting the black mush away, and repotting into a sharply draining mix regardless of the season.
Feeding, which is a watering question
Feed only while the tree is actively growing and only into soil that is already moist. Fertilizer applied to dry soil concentrates against the root tips and burns them, which produces brown leaf edges that look exactly like drought damage. Water first, then feed, or use a dilute feed as the watering itself.
A balanced liquid feed at half the strength on the bottle, every two to four weeks through the warm growing months, is plenty for a tree in a small pot. Stop or reduce sharply when growth slows in winter and after any repotting, and do not feed a tree that is shedding. Free-draining bonsai soil holds very little in reserve, so little and often beats occasional heavy doses.
Once or twice a year, flush the pot: water it through several times in a row with plain water until it runs clear. That washes out accumulated fertilizer salts, which otherwise build up in a small volume of soil and show up as a pale crust on the surface and scorched leaf margins.
What to note down
Keep a simple log of watering dates for a couple of months in each season. You are not building a schedule from it, you are learning the interval your particular tree wants in your particular room, which is the thing no general guide can tell you. After a season you will have four numbers, one per season, and checking the soil becomes a confirmation rather than a guess.
Also record the dates you feed, so a month does not quietly turn into three. And note any watering change you made immediately before a bout of leaf drop, because that connection is obvious in a notebook and almost invisible in memory.