The most common perennial weeds are common bermudagrass and yellow nutsedge. Bermudagrass, often called wiregrass, spreads by creeping stolons and rhizomes. Thoroughly remove all plant parts from the garden when hand-weeding because bermudagrass can reroot into the soil. Yellow nutsedge is often called nutgrass, but this plant is a member of the sedge and not the grass family. Yellow nutsedge reproduces by underground tubers.
Mulches can be the easiest and most effective way to control annual weeds in the garden.
Mulches may also suppress perennial weeds. Mulches control weeds by preventing sunlight from reaching the soil surface. Light is required for the germination of certain weeds, and light is required for the growth of all green plants. Organic mulches cool the soil surface, which is beneficial during hot summer days, but may reduce crop growth in the spring. Avoid overmulching, which can reduce oxygen levels in the soil.