i do not know the actual amounts, but "white vingar", "table salt", "bleach", and water. worked pretty good for my mom and me. one or 2 gallon hand pumped airless sprayers.
we have dogs, and also spraying up against lake edges. and we didn't want to make anything deadly sick or like. it burns the leafs up real nice. and takes a couple times to get down near roots. ""best bet"" to help kill out the leaves is during a hot summer day, and you know there will not be any rain for a couple days. on another note it is by no means one time fix and never half to re-apply. but it has taken out some poison ivy, and other grasses and weeds and left dead spots for a couple months.
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myself i tend to stay away from "complete vegetation killer"" products. i have to much rain, and rain run off that feeds into lakes. don't get me wrong i will use it, if i have to. but i just have had no need up to this point to do so.
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on another note. if your rock driveway is rather old and new gravel just been placed here and there over the years to fix pot holes and like. and there is a lot of dust and mud near surface of the rock. you might look into rent a "land pride grader" from a local tractor dealer / repair / tractor parts place, or place "WANT" ad on craigslist, the land pride grader is kinda like a double box blade. it sifts the gravel causing smaller size dust and mud to fall down while rising the larger rocks to the top. this can help remove a lot of the initial food source for plants to grow within the rock driveway. and at same time give the driveway an almost new look like fresh gravel was just put down.
check out
Everything Attachments | Skid Steer Attachments, Tractor Attachments, 3 Point Hitch Attachments, and Farm Tractor Implements. they have a good sum of videos for different attachments and actually using them and showing results.
if you had a 3pt box blade with rippers / sacrifices on it. you might be able to do same thing as the grader i am talking about. but perhaps not as good or as quick.
besides the land pride grader, box blade, a rear blade would be an addition weapon in the arsenal in maintaining rock driveways. along with perhaps a 3pt rake of some kind.
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i realize above i am saying forget the herbacides and like. and just take care of the actual problem. and fixing root problem will more likely be higher initial cost. but *shrugs* i think you would be happier and less money spent in the long term of things. well i take that back, if you have a tractor to begin with. if not you may be better off band-aid approach and applying herbicides and like to the rock driveway, till you can find a local neighbor or hire someone to come out and take care of the driveway for you.
for other info on maintain rock driveways, do a search in the "projects" forum of TBN. there is a good amount of threads of folks building rock driveways and most of them go into maintaining rock driveways as well. also on some snow plowing threads. a good some of detail in maintaining rock driveways can be found there.
