One tree decides when a city's cherry season starts
A city's cherry blossom season begins the moment five or six flowers open on one specific, numbered, official tree.

A cherry tree in spare ink line, drawn plain, not in bloom. Near the end of one branch, five or six
flowers have opened; everything else on it is still a tight bud. A low railing rings the base. A
small post beside it carries a plate: SPECIMEN TREE, and under that, No. 6.
Nobody photographs this tree for how it looks. They photograph it for what it just did.
Why does one tree get to speak for a whole city?
Because somebody has to, and a single fixed point is the only way to compare one year with the next.
Japan's meteorological agency declares the start of cherry blossom season city by city, and each declaration is tied to one designated specimen tree — there are 58 of them nationwide, one per monitored city. An official watches that tree, and only that tree, through the season. The date gets recorded, published and compared against the same tree's date the year before.
A whole city's spring, in other words, is reported through a single sample.
What counts as "open"?
Five or six flowers, checked by eye, on the specimen tree.
That's the entire threshold — not a percentage, not a colour change across the canopy, just a small countable number of blossoms on one tree. It sounds almost too casual for something that makes the evening news, and that's rather the appeal of it: an enormous seasonal story, and the trigger is a number you could count on one hand.
Why is full bloom judged separately?
Because "open" and "full" are two different questions, with two different thresholds.
Opening is five or six flowers. Full bloom is a much later call, made once roughly 80% of the tree's buds have opened — effectively the whole canopy, rather than one branch. The two dates are usually a week or more apart, and both get reported, because somebody sent out at dawn to hold a good spot is planning around the second date, not the first.
Two dates, one tree
The gap between them is where most of the actual planning happens — a booking made for the opening date and a booking made for full bloom are not booking the same afternoon.
Why put the signage on the shirt instead of the blossom?
Because the sign is the part nobody thinks to draw.
Everybody's mental image of cherry blossom is the canopy at its fullest, or the same tree lit hard from underneath after dark. Almost nobody pictures the railing, the numbered post, or a tree that's mostly still bud — which is the actual moment the season officially begins. Drawing that moment, signage and all, is a small correction to a picture everyone already has in their head.
It also reads as a design rather than a photograph, which is most of what makes it work at chest size: a railing, a plate, a handful of flowers, and plenty of ground around them.
Can I use a tree I actually know?
Yes — a tree and a place name aren't anybody's property.
What the design borrows is a public system: a specimen tree, a numbered post, an official-looking plate. None of that belongs to an agency in a way that stops you drawing your own version of it, any more than a road sign belongs to the council that erected it. What would need permission is a specific published photograph, or an agency's own branded chart — neither of which this design is.
The version worth making is the tree you actually walk past, given the same formal treatment the real specimen trees get — same idea as tracking a season by a line moving north, just fixed to one point instead of a moving one.
Does it print well?
Very — it's line work on a plain ground, which is close to the easiest thing fabric can carry.
A single ink-coloured line, no fill except the handful of blossoms, and a small block of type for the sign. The blossoms are the one place to be careful: five or six dots read as flowers only if they're distinct and a little irregular, not a uniform cluster. Too neat and they read as a graphic element instead of a live count.
Bone, oat and pale grey grounds all suit it — anything the ink line can sit on without competing. One ink colour for the tree, a second for the sign plate.
How do I get one made?
Describe the tree at JustOG — how many flowers are open, and what the sign should say. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to order and shipped.
Designs other people have published are in the shop.
Somewhere tonight, an official is standing under a tree with a clipboard, counting to six.