How to stop weeds in flower beds
Buy a roll of the material shown below from any DIY or garden centre. The key is that it has to allow water through it so that the plants roots can still receive the water.
Hold it down with Bricks or sometimes you get given metal clips. Cover the area with wood bark or even stone chippings for effect.
To plant, cut a round hole with some scissers, large enough for your plant. The weeds will be hard put to grow, and any that do can easily be pulled.
The same material would go under a decking, or patio, or gravel area to stop weeds growing up though.