Treated pine was put into the ground as garden edging above ground about 3 months ago. I would like to paint (not stain) it a colour close to the pine (so when it peels it won't be noticeable that much) as there's some black stuff on it from the decking I had installed, but I'm not sure which paint to use because it's also butted into the soil. I also have some bird poop to clean off it so I don't know whether I have to sand it or not after doing this. Can you please help?