How to keep weeds out of a garden?

Im here to Give you your needed answers :) ! I'm 20 years old and have been working with plants and related stuff since i was 11 with my parents owning a landscaping Business i know a lot! After you lay the tarp down and make sure its help down good ( i usually get metal steaks, it helps because even eventually soon enough the bark dust you lay down willdissipatee andyou'lll have troubles with the tarp again so i suggest metal steaks) which can be found at a garden store or meijers fairly cheap. and then whatyou'lll do isyou'lll cut a good foot sizelengtht in the tarp where you want your plants...it may seem like a big space but plants and flowers grow...trust me :). then when you get done cutting out all your holes plant the flowers about a foot into the soil, another way to help and keep them healthy is to put half a handful of fertilizer in the dirt before you put the plant down in the dirt. Then cover it up with the soil. Then when you get them all planted water it all and have fun with the red bark dust :) it will look great! just make sure you dont put the bark dust to close to the flowers cuz it can restrict the oxygen and water to get in that it need a little is good but not to much! I think youll do a great job! and it will look amazing! and a good weed remover is Roundup, our company uses this its very helpful and works fast! i wish you the best of luck hope it turns out!