occasional writing about gardening, small electronics, and long walks
The little fig spent winter by the north window and dropped every leaf, which is exactly what it is supposed to do. This week I slid it out of the pot to check the roots: circling a bit, but healthy and pale. I teased the outer inch loose, trimmed two thick roots, and moved it up one pot size with a gritty mix.
Note for next year: do this two weeks earlier. The buds were already swelling and a couple snapped off while I worked.
The resistive probes you find for a dollar corrode within a season because they run a DC current straight through wet soil. The capacitive ones avoid that by measuring at a fixed frequency instead. I potted the electronics in a blob of hot glue, left only the sensing pad exposed, and it has read steadily for months.
Calibration was two points: bone-dry pot, then the same pot an hour after a full soak. Everything useful happens between those numbers.
Fourteen kilometres, mostly frozen gravel. I have walked the short loop a
hundred times but never the full perimeter. The far side has an old pumping
station, brick, roof half gone, with a hand-lettered sign that just says
NO ENTRY — 1987. Someone has kept the padlock oiled anyway.