Weeds are as much of a problem in garden beds as they are on lawns. They can take away from the natural beauty of a well-groomed garden bed. Weeds can be killed as they emerge with postemergence herbicides, but you can also prevent weed seeds from germinating with preemergence herbicides. When applied at the right time, such herbicides will prevent any weed seeds in the ground from germinating, allowing your garden bed to look great for a long time.
Plant your garden beds as you desire, and remove any existing weeds. Ensure that you get all of the roots to prevent the weeds from growing back.
Apply your preemergence herbicide to the garden soil at the indicated rate on the bag. Apply when the plants are dry to prevent the granules from sticking to the plant leaves.
Irrigate the planting beds to wash off any granules that stuck to plant leaves and to activate the herbicide.
Apply another application eight weeks later if your planting bed hasn't filled out enough to prevent sunlight from reaching the soil. Dense planting beds will naturally deter weeds from growing.