5. Don’t allow weeds to go to seed and multiply, and don’t compost them.
6. Mow away from your garden beds—lawn clippings may contain weed seeds.
7. To suppress weeds once you’ve planted, layer about 7.5 centimetres of mulch over bare soil between plants. Commonly available mulches include straw (not hay—too many weed seeds), cocoa bean hulls and shredded cedar bark. Basically, mulch keeps weeds down by blocking out the light they need to germinate.
Weeds to watch for
Summer annual (one season) weeds such as lambs’-quarters (Chenopodium album) and ragweed sprout in spring and go to seed in late summer and fall. Winter annuals such as common chickweed (Stellaria media) sprout in fall and go to seed in spring or early summer. Annual weeds can grow quickly enough to spawn a couple of generations in a single season if you let them go to seed.
Biennial weeds, like Queen Anne’s lace (Daucus carota) and burdock (Arctium lappa) form roots and a rosette of leaves the first year, then flower and set seed the second year.
Perennial weeds, like dandelions, Canada thistle, quack grass and creeping Charlie are long-lived and have large, vigorous root systems. Many of them spread by both seeds and stolons (horizontal, above-ground shoots), or rhizomatous roots (horizontal, underground stems). They’re the toughest weeds to get rid of because of their ability to regrow from tiny pieces of root.