You will need to use both spray and granular products to prevent weed growth.
I love flowers but I hate weeding and then the inevitable return of the weeds in the same flower bed I just cleaned out. If you're like me, then you may benefit from what I have learned.
You really can't use weed spray near flowers or shrubs because the overspray will kill them. But do spray driveways and other areas without plants. You can even spray a small edge along a sidewalk if you don't mind a small brown edging to it. Remember that weed sprays (I like Round-up 360) can cause cancer so make sure to spray on a non-windy day, cover your arms and legs with long sleeved and long legged clothing, don't wear sandals and wash everything including yourself after spraying is done. Any skin that was exposed should be rinsed with water that has a tablespoon of baking soda in it to neutralize the spray. It's hard to find a weed spray that is organic and healthy that actually works . You can try some of them, as I have, but the weeds will be back shortly (just sayin').
Now what to do around plants? There are granular pellets like Preen, Amaze or Casoron that you can sprinkle around your plants AFTER you weed the first time. I have used Preen and Amaze and this year I'm trying Casoron. My findings are that you have to weed again with Preen within two months. Amaze only has to be re-applied once again mid-growing season, so only two weedings all summer. Casoron is promoted to last for a full year. That remains to be seen this summer. Preen is pretty easy to find in stores. Amaze is sold by Home Depot and Casoron by Lowe's. Oh! and BTW these products not only prevent weed regrowth but also feed your flowers and shrubs. But don't use them on ornamental grasses. They don't know the difference from weed grass.
By using these products I find I can enjoy my plantings without being a slave to them.
Note: Don't use these on vegetable gardens. You need a food safe product. Actually lining your spaces between your rows with newspaper is a safe and inexpensive solution for your vegetables. You still have to weed between the plants in the rows but this cuts the work down considerably.