The dew does not turn white. It looks white, which is a different claim and the one the name is actually making: a low sun catching a whole field of droplets at once, so that the grass appears to have been silvered overnight. Get closer and it is only water.
What matters is that it is forming at all. Dew needs the ground to lose heat to a clear sky until the surface falls below the dew point, and that requires nights long enough and still enough for the loss to add up. Everything the calendar has claimed since Risshū has been about heat receding. This is the first kō that depends on actual cold. It also contains 重陽, on September 9 — the last of the five seasonal festivals, and the one that has most thoroughly disappeared from modern life.
In full season. Salt, high heat, grated daikon.
Fat content climbs through autumn — hence the old line about not letting your daughter-in-law eat it, a joke that is either about jealousy or about the fish going off quickly, depending on who is telling it.
The first fall now. 栗ご飯 — chestnuts cooked into rice — is the customary dish of 重陽, which is why the festival's other name is the chestnut sekku.
Still running strongly through the middle of September.
Mid- and late-season varieties. These keep better than the August ones.
Denser flesh, finer skin, fewer seeds. Also eaten at 重陽 — 'aubergine on the ninth wards off palsy' is the traditional formula.
Coming into season now and central to the harvest-moon offerings later in the month.
The start of the mushroom weeks. Torn rather than cut, and cooked hard enough to colour.
There is an awkwardness worth admitting about the chrysanthemum here. 重陽 was fixed to the ninth day of the ninth lunar month, which in the old calendar landed in mid-October — when chrysanthemums are genuinely at their best. Moved wholesale onto September 9 in the solar calendar, the chrysanthemum festival now arrives about five weeks before the chrysanthemums do. Hagi and cosmos are what is actually flowering in this kō.
The last of the five sekku. Odd numbers were yang, nine was the largest of them, and nine falling on nine made the day both auspicious and dangerous enough to need warding. The chrysanthemum did the warding: 菊酒, sake with a petal floated in it or steeped overnight, drunk for long life. The refined version is 被綿 (kise-wata) — floss laid over a chrysanthemum on the evening of the 8th, left to take up the dew and the scent, and used the next morning to wipe the face and body. Worth noting that the floss was 真綿, silk wadding, not cotton: cotton barely existed in Japan when this custom was at its height. Of the five sekku it is the only one to have effectively vanished — no cards, no supermarket display, nothing.
草 grass, 露 dew, 白 white — くさのつゆしろし. 白露 is also the name of the parent solar term, so this kō is essentially the sekki restating itself, which happens only a handful of times across the 72. The white is not just descriptive: in the five-element system autumn is the season of metal and the colour white, the same logic that gives the autumn wind its old name 白風 (hakufū). 露 on its own is a firmly autumn seasonal word in haiku, and it carries the standard connotation of things that do not last.
Dew has been forming for weeks, and in the highest places the first frost is now closer than the last hot day.
Places like Nagano, Kōfu, and Karuizawa get the best dew in Japan, for the same reason they get the best fog: cold air pools on the valley floor overnight and cannot drain away.
Nights do not cool enough for dew to be a seasonal event. The kō describes a mainland phenomenon.
The white effect needs a low sun behind the droplets. Half an hour after sunrise it is already ordinary wet grass.
Chestnuts, rice, a little sake and salt. It is the 重陽 dish and the simplest way to observe a festival almost nobody observes.
菊酒 in its unfussy form: one edible chrysanthemum petal in a cup of sake. The Heian court left it overnight; an hour is enough to get the idea.
"Let me brush my sleeve against the chrysanthemum dew just enough to be made young again — and leave the full thousand years to the flower's owner."
Laundry left out overnight now comes in wetter than it went out. Dew is the reason, and it starts this week.
The gap between the day's high and the night's low is at its widest point of the year. A thin layer that can come off by ten in the morning.
Dew on tarmac, painted lines and metal plates makes the first hour after dawn the slipperiest of the day, especially on two wheels.
被綿 is a strange and rather beautiful piece of technology. The problem: dew is the most fleeting substance available, gone within an hour of sunrise, and it was believed to hold the flower's power to extend life. The solution: lay silk floss over the flower the night before and let the floss do the collecting, so that in the morning you are holding something that has already caught what would otherwise have evaporated. It is an entire apparatus, built by a court with considerable resources, for the purpose of keeping hold of water for twenty extra minutes. Whether or not it worked is beside the point. Somebody looked at the least durable thing in the garden and decided it was worth the trouble. What's the least durable good thing in your own life right now that you haven't built any equivalent of silk floss for — worth catching before it evaporates, even if you can only hold it a little longer?