I live in a Mediterranean zone 11 area. Winter precipitations are relatively high, but irregular. Wind drafts are common. Frost has not been observed (within my lifetime) but hail strikes from time to time, even if surface temperatures are above freezing.
The same plant is often marketed as Vinca and often referred to as Catharanthus (in catalogs), but it's the same bushy type that I encounter. Recently, I came across the new miniature "superstar" hybrids and I bought two. From what I learned so far, the plant is a perennial, but is locally treated as an annual. The main reason, I suspect is its susceptibility to fungal rot, such as the wilt fungus (Fusarium / Verticillum...). I have few specimens which I bought a month ago and so far seem to be growing well and showing no signs of disease. I recently bought few with a different color. The next two months will be cooler but comfortable, allowing the newcomers to grow before the onset of winter. (Plants may exhibit some growth in October when the first rains appear and temperatures are not too low)
I am planning to grow them as perennials. My first reason being the challenge. The second one is knowing their growth habit and see how they respond to pruning, and the third is to attempt to grow them from seeds and cuttings. Some of the recently bought ones have already shown their emerging seedpods which are yet to mature. I will do my best to gather the seeds before the seedpods explode and scatter them in all directions.
How I grow them... - All my Vincas, along with other small plants are in pots. The pots are used to cover the bare soil under trees, where the tree roots may be too invasive for them. This gives me the double benefit of ease in tending the pots, and clearing the area while tending the trees. This setup also allows me to save water while watering the small plants. All pots (except for my aroids) are planted in a standard potting mix.
The winter is coming... - Should I keep the Vincas outside in the rain? They are susceptible to overwatering, and they are planted in plastic pots. Should I worry about the rains and move them to a dryer location? Will drafts kill them, or will they just go dormant?
