Use an old spray bottle filled with a path weedkiller. Mix the solution in an old 5ltr plastic container. Only target the weeds. to cover the whole area with a watering can and weedlkiller (as the manufacturers would like you to do) is far too expensive. It is now not possible to buy large quantities of weedkiller due to the fact that you can make bombs out of it. My...
Have you got a membrane under your gravel? as this will stop most of the weeds getting through and any you do get will be rooted in the gravel not the soil and should be easy to remove either by hand or with a good weed killer.
Cover entire area with gardening mesh, then cover with 3-4" of gravel, this keeps area weed free for at least 2-3 years, and when weeds do grow they're very small and are easily removed.
Use an old spray bottle filled with a path weedkiller. Mix the solution in an old 5ltr plastic container. Only target the weeds. to cover the whole area with a watering can and weedlkiller (as the manufacturers would like you to do) is far too expensive. It is now not possible to buy large quantities of weedkiller due to the fact that you can make bombs out of it. My method is relatively inexpensive.
I follow advice that I read in a gardening article some years ago. I apply weedkiller to my gravel drive by watering can twice a year: 1st at the end of February, 2nd at the end of June. Works very well.