Thanks for the tip. Scrubbing pots out isn't one of my favorite things to do, but this should make the task easier. Vinegar to the rescue once more!

If you are getting scale in your pots means the water is hard (alkaline). Alkaline water makes the soil alkaline. Alkaline soil is not liked by bacteria which help in nutrition. Alkaline soil is loved by slugs. Why not just make it into a practise to add vinegar to the watering can and drop PH to 6. Helps in making soil acidic(attacks shells of slugs). Also think of adding elemental Sulphur to soil which in turn over time makes the soil acidic plus any of the other sulphates eg. magnesium sulphate makes the soil acidic and provides magnesium at the same time. You can also use dilute battery acid (sulphuric acid) if you can get it. Nitric acid dilute provides nitrates.
Just my two cents worth.
Regards,
Masud.

I wonder if that would also remove the white scale that sometimes builds up on my raised bed walls (concrete paving stones stood on end)?

I assume it comes from some dissolved salts diffusing through the pavers, and being left behind when water evaporates from the surface.



BTW, I recently noticed (when I crawled under my bamboo) that no shoots were coming up right near the walls of the bed. I often let that patch go un-watered, and I speculate that the edges dry out so often that the roots don't grow into that zone.

When I have time, I think I'll line those RB walls with heavy plastic, to keep that RB from drying out so fast around the edges. It is a shallow layer of half-decent soil over clay, so it probably doesn't retain much water.

2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . March 2013, before growth spurt