Vinca is a perennial that includes three species and a number of cultivars. All three species and their cultivars grow and propagate easily. Vinca minor and Vinca major are considered invasive in some states. Vinca major, Vinca minor and the Madagascar periwinkle, Vinca rosea, find use in the landscape as vinelike flowering ground covers.
Vinca rosea grows easily from seed sowed at a depth of 1/4 inch. The seeds germinate in 10 to 15 days and require darkness for germination. Outdoor planting takes place in late fall or early winter in USDA zones nine and 10. The Madagascar periwinkle grows as an annual in all zones except 10, where it is hardy.
Collect seed pods from greater and lessor periwinkle after they dry on the vine. Plant in the fall at a depth of 1/4 inch and plants will sprout the following spring. Greater periwinkle seeds do not germinate reliably and vegetative propagation is the best method.
Vinca naturally propagates by tip layering. The tips of growing shoots in contact with the ground will form roots and the plant spreads. Serpentine layering produces several plants from the same growing shoot. The shoot should be slightly damaged by scraping a small section from the underside of the vine and then the short section should be buried.
Layering takes place in the spring and gives the plants summer and fall to root and establish new plants. Transplanting takes place after severing the new plants from the original shoots.
Vinca propagate easily from cuttings and slips and produces the most plants from a single plant. A piece of stem with a leaf attached placed upright in water or a growing medium such as vermiculite will grow roots. After sufficient roots have formed, the plant is moved to a pot of soil to continue growing.
Sections of root cut from a growing plant will grow into individual plants. The ability of the plant to grow from root cuttings is the bane of people trying to remove it from an area. A small piece of root left in the ground will grow a new plant.
Vinca divisions taken in the fall and put into pots or moved to other locations grow into separate plants. The plant is lifted from the ground and separated into several individuals by cutting and pulling the plant into sections. The sections begin growing immediately given proper growing conditions.
Divisions produce a few new plants quickly and reliably, but production is limited to just a few plants from each individual. Propagation by division is the easiest way to produce new plants for transplanting.