Outdoor cover for the popular analog Capacitive Soil Moisture Sensor v2.0 (according to comments, this also fits version 1.2).

No soldering changes are required. I just crimped a JST 2.54 mm female connector on the cable. The cable diameter is 4.6 mm (3 cores, 22AWG), but the hole in the cover is intentionally slightly smaller to make a good seal. Use M2.5x10 screws with countersunk heads to assemble the cover. No nuts are needed.

I printed the cover on my Prusa Mini+ with Prusament Galaxy Black PETG - 0.4 mm nozzle and 0.15 mm layer height. The sliced file contains both the box and lid and they are printed sequentially to reduce stringing. PETG is recommended for outdoor use.

I highly recommend coating the sensor with conformal coating - I used some basic acrylic coating for electronic boards and coated everything except the pins inside the male connector on the sensor. I am not too worried about any water entering the case, the main reason is to coat the edges of the board, otherwise it might absorb water. If you are worried about any water entering the case, you can seal it with a coating of your choice.

I use the sensors with ESPHome and Home Assistant.