Tordon RTU will also kill all the evergreens as it leaches through the soil.
Hence the scalding suggestion; I know I've seen something out there that was basically designed to spray ~200F water for some other industrial purpose, and I've used just-under-boiling water to wilt weeds, then seen them turning brown the next day. Of course, as it cools, it's just watering the desirable plants six inches away.
I would assume the reason there's not some sort of hot water weed sprayer on the consumer market is because some idiot would manage to severely scald himself or his kids with it through sheer stupidity and sue the crap out of the manufacturer no matter how many safeties and warnings it came with. OTOH, if you're bright enough to keep pressures low, fittings tight, the spray area clear of people and pets, inspect hoses regularly and use a spray wand too long to accidentally hit your own body, it should be a viable solution.
