P.S There are a couple of pups growing beside the main plant. If I can't save the main plant, would it be worth trying to separate and replant the pups?

I use a BT spray once a week as soon as I start getting green tomatoes and that seems to prevent the caterpillars from eating them. The first year I grew tomatoes they ate holes in most of them but I've used the BT every year since with no problems. It is an organic pesticide that only works on caterpillars. The kind I buy is a concentrate that you mix with water. There is also a powder but I find it messy-looking and harder to apply than the spray.

The relatively mild winter is precisely the reason why this is happening. When the temperature is above freezing, water seeps into the minute spaces between the layers of which bluestone is composed. Then, when the water freezes it expands and causes flaking of the surface. This doesn't happen in winters where temperatures consistently remain below freezing. With due respect to hollysprings, I would not follow her advice about gutters. There's a reason why your neighbors don't have them. In a really cold climate like you have in the Adirondacks with temperatures routinely in the -20 to -25 range, gutters encourage ice dams on the roof - even metal ones - which are potentially much greater problems than the flaking bluestone. By all means regrade if water does not run away from the house and keep an eye on the foundation from the inside, but I would not worry over much about the bluestone. It is, after all, a protection for the actual foundation and will endure minor flaking like this for a century or two. Putting anything on it like hydraulic cement is unnecessary and undesireable. I'd also suggest that annual repointing of foundations is just common sense maintainence in a severe climate like yours - it doesn't mean that water is infiltrating the foundation - just moisture from condensation can damage mortar at -30 degrees. What I would be careful about is making sure that no water is getting behind the bluestone. Trapped there, it could do some harm to the actual foundation and would eventually pry off the slabs. All in all, your neighbors and other people who have lived in the Adirondacks - one of the most beautiful places on the planet - are your best source of information about what to do and not do.

Please don't assume that I assume you're a dummy! I have to ask: The stain sealer is water based or oil based? And is the 'white powder' coming through the sealer or have you already applied the lacquer? If something seems to be 'coming through', and you have lacquered over the sealer already, my first thought is that a) the sealer wasn't fully dry and so is still releasing VOCs (off-gassing) or b) the sealer and lacquer aren't playing well together (incompatible bases). Here is a link that might be useful: HeadSpace Custom Carving and Textures