Plant Vinca when evening temperatures are at least 60 degrees, typically in mid-May. This plant is heat and drought-tolerant and makes a great plant for warmer parts of a garden area. Plant Vinca in average soil in full sun to partial shade location. Space the plants 12-15 inches apart. Water well after planting. After that, weekly watering is all the plant needs. Mulch around the plants to help retain moisture. Use a general-purpose fertilizer once or twice a season.