Florivern Herbarium · Sheet HERB-02
Det. — species determination
Pinus thunbergii
Japanese Black Pine Bonsai
Fam.
Pinaceae
Classic rugged two-needle maritime pine exhibiting deeply fissured corticose bark, powerful surface root flare (nebari), and disciplined pad ramification.
Hab. — where it grows wild
Coastal maritime zones of Honshu, Shikoku, and Kyushu, Japan
HERB-02
Characters
Group
Bonsai & Ligneous
Setting
Outdoor
Size class
Tabletop / Compact (< 40 cm)
Temperament
Specialist / Collector
Animals
Mild Irritant / Caution
Sheet II — Conditions of cultivation
How it has been grown,
and what changes it.
Requires free-draining granular bonsai substrate that exchanges oxygen rapidly. Water thoroughly as soon as the surface Akadama granules transition from dark brown to pale tan; never follow a fixed calendar schedule during summer heatwaves or winter frosts.
45% – 70% RH with continuous outdoor air movement
Temperate outdoor seasonal cycle (-5°C winter dormancy to 32°C summer; requires obligatory winter chill hours)
Air temperature as recorded for this species in cultivation. Cold drafts matter more than the average.
100% inorganic granular bonsai mix: 1:1:1 hard-fired Akadama, Hyuga pumice, and Kiryuzuna volcanic gravel (3–5 mm particle fraction).
Height 28–38 cm in training vessel; nebari basal flare 8–12 cm
Sheet III — Animals and households
If a cat, a dog or a child shares the room
Mild irritant
Not recorded as seriously toxic, but contact or chewing can irritate. Handle and place with care.
The record
Needles and terpene-rich oleoresin are not systemically lethal in trace contact but can cause mild gastrointestinal upset or mechanical irritation if chewed by companion animals.
Florivern is a herbarium and a shop, not a veterinary authority. If you suspect a plant has been eaten, call your veterinarian or an animal poison control line.
Sheet IV — Monograph
Notes toward cultivation
Candle Decandling & Seasonal Ramification
Pinus thunbergii is a vigorous two-needle coastal pine whose miniature proportions depend on disciplined mid-summer decandling (mekiri) and autumn needle thinning. Strictly an outdoor ligneous specimen, it requires full solar irradiance and winter dormancy below 7°C to sustain vascular vitality.
A tree, not a houseplant
Japanese black pine is a hardy outdoor tree. Kept indoors it weakens quickly, because it needs strong sun, moving air and a cold winter rest. Think of the bonsai as a full-size pine held small by technique, with the same needs as its wild relatives.
In cultivation
Grow it in full sun in a free-draining, mostly inorganic bonsai mix. Water thoroughly whenever the surface begins to dry; in summer that can be daily. In winter, protect the roots from hard freezes, since a shallow pot offers far less insulation than open ground.
Styling through the seasons
Most of the work follows the tree’s growth cycle: shortening or removing new candles in early summer to encourage a second, shorter flush, and thinning old needles in autumn so light reaches the inner branches. Timing depends on the tree’s vigor and your climate, so observe the tree rather than a fixed date.
Common problems
Yellowing inner needles in autumn are often normal seasonal shedding.
Weak, pale growth usually means too little sun.
Persistently wet soil leads to root decline; black pines dislike stagnant water.
Supplementary plates
Plates show cultivated individuals, not a type specimen. Leaf form, color and habit vary between plants of the same species.
Sheet V — Cited in the Journal
Further reading on this plant
Held in the Store
Specimens and materials
Pinus Thunbergii — 12-Year Tokoname Bonsai
Low Stock
$420
Forged Sanjo Carbon-Steel Satsuki Shears
Low Stock
$88
Each specimen is an individual plant; size and form differ from the plates on this sheet.