Vinca (Catharanthus roseus) an excellent selection if you have little time to tend your garden. Useful in borders, flowerbeds, rock gardens and containers, the vinca flower provides instant color wherever it grows. Plant care: Pull up any weeds growing around the vinca. Clear any debris, such as fallen leaves, twigs or rocks from the ground. Spread a 1- to 2-inch layer of mulch around the plants with a trowel or garden fork. Keep the mulch two to three inches away from the plants' stems to prevent the development of rot