Boiling water will do it.
Weed and Feed
Any home remedy is going to be non-selective. To the extent that it works, it will work on whatever you put it on.
I think pulling weeds is just part of the human existence. I have put down plastic, landscaping cloth, mulch, vinegar and everything comes back. I am nagged by my son not to use chemicals, but can no longer stand the heat to grass. I am going to bargain with a yard service soon!
I spray weeds with a solution of 1 gallon of 5% white vinegar, 1/4 cup salt, 1 tsp dish soap. Do it in the morning of a hot sunny day and the weeds will die off in 12-24 hours. Be careful what you spray..it does not discriminate.
White vinegar has never failed me. I buy it in bulk and pour it into a weed sprayer that I keep handy in the shed. The hotter and sunnier, the better it works. Like Judy said, be careful you don't overspray onto something you don't want to kill.
There is nothing that you use to kill weeds but not flowers or plants or even young trees. Be very careful and if you have a lawn service do it, make sure they use a solution that does not kill evergreen trees. Here in Wisconsin, lawn services were using a harsh mixture and when applied, the over spray hit the trees and the branches started turning brown and the following year, the tree started dying. Bushes also, so be careful. Maybe pull weeds around the plants and try a weed killer more in the open. Good luck.