I have used this in my gardens with a garden sprayer. You can use it with the sprayer just hold the sprayer close to the ground and spray lightly so it doesn't get in contact with your flowers. Also, make sure it's about 12 inches or so away holding the sprayer against the ground. Another item I use a lot is Preen. It could be a lot of work at first depending on how much weeds you have but if you pull and scrape up the clovers put a good amount down it should keep the weeds at bay. Try to use only preen as I have tried other products and they haven't worked. Something to keep in mind in the spring when you are adding new soil and getting your flower gardens together and before adding mulch mix a lot of preen into the soil before laying that new soil down. I know it can be a little costly but trust me it works and will save you from a lot of back wrenching work of weed pulling. Try not to use other products like Preen as I have found out for myself they don't work. I have found this will last pretty much the whole planting season. You can sprinkle more during the summer on top of the mulch if you do see some weeds breaking ground just be sure to pull those weeds because preen will not kill anything that has already popped up. I hope I have answered your question and good luck with the clover.

Vinca is pretty hardy..but check the label on weed be gone ..if its not listed i would try putting it on a FEW vinca plants and observe if they survive...you will know in 1-2 days.