Just wondering, you have that planter under a roof overhang. Is it close enough that moisture drips/runs off the roof onto the planter? If so, you're not the only one that's watering it
Just a side note about moss and soil acidity. Mosses can grow where the pH isn't especially acidic. Moss growing in lawns, which is where the lime vs. moss issue usually relates, implies a number of undesirable growing conditions for the grasses. If the soil is acidic enough that it reduces the grass's competitiveness due to reduced nutrient availability then lime will help the grass grow better - as long as the other problems are also addressed. It doesn't directly kill the moss by itself but helps the grass, and one wouldn't want to apply lime without a soil test to first confirm that the soil really is too acidic. Pushing the pH too high can also have a negative effect on plants.
