>>2746844rubber/spray gloves, rubber boots you can wash off, respirator with organic vapour cartridge, long pants and long sleeve shirt, goggles if really worried, otherwise just safety glasses. Wash clothes separately after use.
Completely unnecessary for your kind of use (except maybe some gloves) but that will keep you safe.
I work in conservation so I spray litres of all sorts of herbicide daily, with that use it's more important to be appropriately protected. Most people who work extensively with herbicide will notice a bit of glyph sickness (or herbicide sickness) if they're huffing it all day, all week. If you're worried about a little bit of spraying in the backyard, do NOT look into what's used for agriculture, organic or otherwise.
>>2747094trees when cut will often reshoot/begin epicormic growth. The point of herbicide dabbing is to kill the plant to the point it wont regrow at all. Not all plants will survive the girdle though so that's fair if it works.