Posted: 05/07/2014 at 12:54
I once did a new bed with plants inserted through weed suppressant fabric and chipped stones. Despite cutting generous crossed and folding back the fabric, two years later all the plants were gasping for space as they had grown big and strong and wanted room. Removing the stones and the fabric was a nightmare but I did eventually liberate all my plants.
I would suggest a better method would be to mark out your new beds and then apply a dose of glyphosate to kill off any perennial wildfowers and grasses. Once this has worked, dig the soil over adding as much well rotted manure and or garden compost as you can.
Plant your new treasures with enough space in between to hoe any new seedlings and taking into account there eventual height and width. Water them in well so they establish quickly. Keep them watered well until the autumn rains start so they don't get checked by drought. Then it's just a question of hoeing regularly to remove any unwanted seedlings.
Your border should get established quickly if you do the soil preparation right and then spread to cover all the soil. There will always be new weed seeds arriving on the wind or dropped by birds but hoeing will deal with these until there is no bare soil visible for them to set up home.