Growing Perennial Vinca Upright

Remove any existing vegetation in a planting location that receives at least four hours of direct sunlight each day. Prepare the soil by tilling with a rototiller or turn it with a shovel. Mix 3 to 4 inches of organic matter into the soil. Add sand to clay soil to improve drainage. Vinca plants will tolerate nutrient poor soil, but will not grow well in soil with poor drainage. Plant them in a raised flower bed if the soil drainage is very slow. Mix a 16-4-8 granular fertilizer into nutrient-poor soil at the rate recommended by the product manufacturer.

Start seedlings indoors three to four months prior to the last expected frost in the spring in cool climates. Sow seeds directly in the garden in warm climates. Plant vinca seedlings after the last expected spring frost. They may be planted at any time throughout the year in zones 10 and 11. Dig shallow holes for the vinca plants with a hand trowel. Plant them no deeper than they were growing previously. Set the plants 1 to 2 feet apart depending on how solid the row should be. Space them 1 foot apart for a solid row and 2 feet apart to allow some garden space between plants.