Periwinkle can grow thickly enough to crowd out weeds.
The best cure for weeds is prevention. Plant weedy spots with thick-growing ground cover to minimize weed growth. Ground cover works well on banks, in sun or shade, under fencing where it's hard to keep weeds down, beside outbuildings, and even under trees where it's too shady for grass to grow. It's important to start the ground-cover bed in weed-free soil, however, so the ground cover can take over without competition. Turn the soil with a rototiller or spade, let the weeds sprout, and then turn it again. Repeat this until the weeds are almost gone.
Choose a ground cover that will spread vigorously and grow thickly enough to crowd out any weeds that try to get in. In shady areas, try ivy, pachysandra, barrenwort, wild ginger, or periwinkle. In sun, try creeping junipers, daylilies, ground-cover roses, or other plants that are suited for your climate.
For good results fast, buy plenty of plants and space them relatively close together. If this is too expensive, spread plants farther apart, and mulch the open areas to discourage weeds. Plan to keep a close eye on the new garden for the first year and pull up or hoe down any weeds that appear. Water and fertilize as needed to get the ground-cover plants growing and spreading quickly. Once they've covered the soil solidly, there won't be any space for weeds.
Unfortunately, no matter how diligent you are, weeds are bound to crop up somewhere eventually. Use a sharp hoe to scrape off weeds, especially annual ones, instead of stooping and pulling them. Using a hoe is quicker and easier than hand-weeding, plus it does a superb job. If you catch weeds when they are young seedlings, a single swipe will eliminate them. If they are older, cut them down before they go to seed to prevent future generations of weeds. If your garden is too small for a long-handled hoe, get a small hand tool with a hoe or scraper on the end.
Perennial weeds such as dandelions may have large underground roots that will resprout after hoeing. When the soil is moist, use an asparagus fork or dandelion weeder (a stick with a forked prong on the end) or the corner of the hoe blade to dig down and loosen the root. Then pull it up by hand.
Keep reading to learn about pruning.